I can't seem to locate that rascal and I'm actually busy for a change, but........All it was, was two pieces paralell about 4'' long say 3/4x1'' bar with groove between them so the corner didn't jamb/interfere with spreading the flanges and of course the V groove was 22.5* with a top counterpart (fuller) at same. I fabbed the bottom swage with spacers in between the V groove void and the bottom base plate and the top tool bevel was cut in the saw..........If I ever make another I would forge the V into a block and then the top into bottom, after which I would cut the relief groove into the bottom piece with a cutoff wheel in a grinder. The hardest part would be to make a tool steel piece at 22.5* to strike into the bottom fuller or........make the top first to form the bottom but a beefy PH or press is needed for that which you two seem to have a handle on............. B) .........Those without can do plan A