As Bulldog has proven, there is a market for such a thing.
As for manefacturing costs, I understand how cost intensive it would be to produce a standardized copy of current trunions...
But how much would it cost to produce simplified blocks? In essense, that's all a rear trunion is: a block with holes drilled in it. The standardized trunions don't have to look like current trunions, all they have to do is WORK like the current ones do. Of course the side folders do need more work to produce the outside hinge: so forget them.
I think the fact that the "new" trunions don't have to resemble the factory ones has been overlooked. Make them a rectangle thats a little longer and needs 4 rivets to secure. This would offer the back of the receiver more structual strength as well.
Forget machining out the center of the block to accomodate the use of the short rivets. Now how expensive would it be to produce a drilled out block of metal? No frills, no cutouts, nothing. A Universal block trunion with the center cut out to accomodate underfolders, but with holes drilled out for use with solid stocks as well.
Of course due to the fact that these trunions no longer use the same 3 rivet patten as the stock units, a Xeroxed template would be included in each kit.
I've been talking to one of the machinists that work in the shop behind mine, and we have been talking about making a customized trunion for my Krinkov. Of course the production unit wouldn't be made like this, but mine will.
The body of the trunion will be made of billet Aluminum. The holes for the rivets will be drilled oversized to allow steel sleeves to be pressed in to give the rivets something hard to grab on to. The Aluminum block will be bolted to a iron plate that will run along the bottom of the receiver all the way to the pistol grip mount. This plate would then be riveted to the receiver from the bottom. The plate will serve as a reinforcement for the pistol grip giving it a solid base to be bolted to. This has traditionally been a weak point to the stamped receivers. We'll get around to it when the time comes.
Anyway, thanks for the input guys. And thank you for a machinests point of view OZ.
**Note: I know drilling the trunion holes is no big deal ozzy, but alot of beginners DO, and would rather have a straight foward no brainer solution to the task.