I bought an FAL X stock to install on my side folder Saiga 12.  The company that made a one-off adapter won't do anymore, so it's up to me. I'm not sure if I should buy a damaged lower, cut the back end off, and weld it to the folder mechanism, or come up with something else.  

Anyone have ideas?  Here's what I'm trying to attach it to:

A FAL fixed stock has the tube that holds the recoil spring inside it... the stock slides onto that tube which projects from the lower receiver and then a screw fastens the stock to the tube and tightens it up to the back of the lower.

If that piece is steel you could get a recoil spring tube, cut it to the correct length and angle and weld it, then just attach the FAL stock in its normal fashion.

It's aluminum, but perhaps I can weld the tube to a plate and screw the plate to the hinge.  Doesn't seem like it'd be TOO hard for a competant welder.  Besides the stock tube, what else would I need?  Is there a nut?

Check Ace LTD, USAThey make adapters for different type of weapons.

It appears as if you have the SMG folder.  Check with them to see if they have an adapter for the Saiga.

In the close out section, they have spacer blocks.  

It seems to me that you could make fairley easily, an adapter that has the hole, threaded for the FAL recoil tube and at the prober angle.  Attach the adapter to the folding mechinisn, then attach the FAL butt stock to the adapter plate using the FAL recoil tube.

I always had the idea to try to mount a standard FAL stock to a para folding adapter.  Kind of like the Armalite AR-18 folding stock.

Good link, thanks!

Gamma, so I need just the tube, the cap and the screw?  Does hte screw go all the way through or just into the cap?  On the FAL lower receiver, does the recoil tube screw into a removable nut or is it welded in place?  This is gonna be a pain in the ass project, but it will be one of two of a kind if I can pull it off.

Check out this schematic from DSA.

You can see how the stock is mounted and what parts are used.

French!  That helps out tremendously, thank you.  Looks like I can get all the standard stock mounted stuff fairly easily, the tricky part is finding a nut that I can weld onto the mounting plate.  OTherwise finding a junk lower that I can mitre saw the back block off of.

Glad I could help, keep us posted with updates.

Take pics also.  You may be paving the way for others.

Good luck