Before we get started on the trigger/trip lever, a word about KARMA triggers.
KARMA makes a fine trigger - mine has never failed, not once. For those of you who have a KARMA trigger, there are some things to think about when designing your trip lever. At left is a GI/KARMA trigger comparison. As you can see, the KARMA trigger comes out of the backplate flat, with no arc on the bottom, as with the GI trigger. This reduces the amount of room you may have for the linkage to fit between the trigger and the top of the bottom handle bracket. On the other hand, the KARMA trigger is narrower, allowing more room for the legs of the trigger linkage to pass between the trigger and the bracket halves. Though it is unnecessary in my "V" spadegrip design because of the reduced profile of the trigger roller lock screw , I decided to give my KARMA trigger an arc. Best for you to wait and see what you will need before changing your KARMA trigger. It takes time and obviously involves some risk of damaging the trigger.
I used a GI trigger as a guide. I placed a drill bit through both trigger pin holes (red arrow) to keep the two lined up. I had ground the bottom on my KARMA trigger when I got it to allow a better reset on my gun, so I had to shim it on top (blue arrow) so I could clamp the triggers and keep them in the same plane. Using a small Bernzomatic oxygen/mapp torch I was able to heat a very small area on the KARMA trigger which allowed me to confine the bend to that same small area. I made the bend at the point where the top of the trigger begins its arc (yellow arrow) . Once red hot, I gently bent the trigger until it had a reasonable arc, let it cool slightly before dipping in water (I didn't want the metal to be too brittle). I then ground the underside of the trigger some. In the drawing above you can see the before and after. The arc is still not as high as a GI trigger, but it's closer and it will give me a little more room to work with, as well as bringing the trigger closer to the original distance from the handle when using the original pistol grip backplate.
I started with the spade. I made a pattern and glued it on some 1/8" plate using spray contact cement. You can click on the image at left for the pattern. It's also on the plans page, along with an alternate grid.
I used a 3" brick chisel to make the cuts. I put a sharp straight edge on it with the grinder. You can find wide cold chisels at a building supply store. Don;t make yourself crazy with a 1" chisel, trying to get the cuts to line up - they won't.

Hard strikes and no filing. Good enough!

I had decided that I would not be able to access the mainspring locking rod with the wrap around configuration, so I made the upper legs of the trip lever straight (See comments at bottom of page). I took a piece of the 1/4" plate I had earlier cut off before making the brackets, and I bent it around the buffer, cut it to length, and added two legs to hold the trigger roller (3).

I put a slight bend in the spade (1).

Then I worked on the 1/4" cotterless hitch pin I had purchased at my local Lowes building supply. When I bought it it had a large key ring through a hole at one end and a spring loaded ball bearing at the other. The shortest one I could find was too long, so I drilled and chamfered a second hole where I wanted it. I then chucked it in the drill press and while spinning, used emery cloth to remove the galvanizing so it would take bluing. I flipped it over and rechucked it then did the same to the other end, then cut it off just past the new hole. Filed it, chucked it back up - more sanding to slightly round the edge.

Big key ring.

After grinding the proper angle on the trip lever risers to accommodate the bent spade, I welded the spade to the frame. I only welded the inside edge where it wouldn't show as much.

I didn't like the large key ring in the roller pin so I sliver soldered a small brass ring, which was plenty to pull the pin out.

The action felt a little sloppy, so I added a spring to keep the trip lever resting lightly against the trigger. I wanted as unobtrusive a spring as I could find. I had a box of assorted springs laying around I had earlier purchased at Lowes, and wouldn't you know it had exactly the spring I needed!
   I installed a longer button head screw (Size 10-24) and made a retaining nut "B". I ground down a hex nut to a shape that was trim and flat. Once everything is Parkerized, I will set the nut with a small punch to keep it in place.
   "A" is a little post that retains the spring on the backplate pivot post (See image - below, left).

Late breaking spring info:

My wife inadvertently pulled the clip off the end of the hanger at left, and a spring popped out that looks about perfect for this project. I tested the leg of the spring to see if it could be bent without breaking and it can. It's a stouter spring than the one I used so it's a bit wider, but it has about the same profile. I think this hanger came from Belks, but I imagine they can be found at about any department store.

Here is the entire spade & trip lever assembly, completed and blued. The spade is face down so you can see how it is attached. I welded only on the inside of the risers. "F" & "G" are cotterless hitch pin & trigger roller.

A) Spring post.
B) Retaining nut.
C) Spring. I bent lower end to wrap part way around post "A".
D) See below.
E) Button head screw (Size 10-24).

D) Threaded Bushing (1/4").
    I did not want the trip lever assembly riding on a threaded button head screw, and I didn't have a screw with a smooth shoulder, so I made a bushing, then threaded it so that the bushing itself would not ride on the threads. Both lower legs of the trip lever are threaded as well. When assembled, the bushing is held tight to the button head screw so that only smooth surfaces move.
    If you want to save some time, don't bother with the bushing. Just drill a hole and run a the screw through it. You could not afford the ammo or time it would take to wear these parts out.
    You want to be sure to thread both legs of the trip lever. This will keep the screw from drawing the legs together and binding on the pivot block.

NOTE: After completion and assembly I felt the spade was too far forward to reach easily. I also realized that the original T-152 design for the round trip lever would actually allow better access to the mainspring locking rod, so I redesigned the trip lever. I removed the spade and heated the upper legs of the trip lever red hot with an acetylene torch and then bent them around the head of a hammer to form a somewhat elongated circle. I then added a single leg to support the spade. Deep welds here.
    Rather than delete all the photos of the first spade I am including both as you may prefer one over the other. I hope this does not get too confusing.

Back of revised trip lever showing attachment of spade.

The "V" spade linkage is in place. I left the spade off and turned it upside down so you can see the linkage relationships better. The safety is set on "safe".