I don't want to upset anyone that did the work so I'm posting links to Saiga12.com.
After it was discussed in another thread about the Russian style side folder I did some searching and found some good info.
It appears the standard AK100 rear trunion can be used with minor mods, clearance for the bolt carrier, and the front locking hook can be made but still looking for dimensions of that.
This thread shows good detail of the conversion, he used mostly Russian parts but you'll find great info and pics, also shows what mods are needed to the AK100 rear trunion (post# 53).
sKott's Saiga 12-C Conversion - forum.Saiga-12.com
This one was done with an ak100 triangle side folder and a home made front latch made from aluminum.
My S12 write-up - forum.Saiga-12.com
I'll post more info when I find it.