I'm trying to figure out where to bend the top lips/rails for my 80% receiver.  It's the Hesse flat from JoeKen.  Can somebody please give me a measurement from a point on the side of the receiver like a trunnion rivet hole or an axis pin to the crease?  Or, the width of the rail on a stamped AK?

My plan is to first bend the upper lips, then fold the sides up.  For folding the sides I went to Home Depot and picked up a 1 1/4" metal flat.  I drilled it to bolt to the botton of the receiver.  Had to grind out a little depression for the ramp that protrudes down forward of the mag well.  Also radiused the metal a bit where the mag dimples are for clearance.  I intend to bolt flat steel to the sides before folding so that I  don't warp the metal.

Any help or tips welcome and greatly appreciated!

Thanks.  I looked around for a decent SAR but gave up after seeing five crappy ones.  Guess I need to go take a closer look.