CJO

I recently repaired a round action of that early type. Quite soon in production they went to the shorter plate. I think I've seen four or five like that, and they were all cracked or broken.

If I remember correctly, the plate was finished square, with a bevel. You may have to build up material so the barrels do not gape open so much, this is what causes the breakout.

Good luck with the welding. I have repaired quite a few round action trigger plates, and the iron has not been of the purest kind. Get ready to herd a lot of slag around.