Looking at a used Arsenal SLR-106 pistol in my area with the ideal of SBRing it after getting the NFA Tax Stamp back.  It looks like its using a side  folding stock trunnion as part of its build.  If this is the case, I guess the receiver would need to be cut for the stock locking/release button before adding the stock, as well as the forward stock locking device.

Does anybody know if this is the case??

Thanks!!

You are correct.

Besides the appropriate stock (poly or triangle), you will need the parts below.

http://www.k-var.com/shop/KR-001BLA.html
http://www.k-var.com/shop/KR-001PP.html
http://www.k-var.com/shop/KR-001FLA.html