TAPCO makes a variety of components for the Saiga line of shotguns that are inexpensive, relatively easy to obtain and some help meet 922r regulation compliance. Among them are new pistons, thread protectors, fasteners and stock sets.
The muzzle thread protector is available for the 12 gauge version of the Saiga shotgun. It carries an MSRP of $12.99 and counts as one 922r part.
Retailing for $8.99, the stainless steel shotgun piston is available for both the 12 and 20 gauge versions of the Saiga line. This also counts as a single 922r compliance part.
Although it does not count as a 922r part, the grip screw and T-nut are useful replacements to have on hand should you need them. They retail for $7.99 and work with the original pistol grip for the Saiga shotguns and rifles.
An M4-type adjustable stock is also available for the Saiga shotguns. It gives you a SAW-style pistol grip and a six-position adjustable buttstock. MSRP is $69.99 and it counts as two compliance parts.
TAPCO makes a variety of polymer magazines for the AK47, AK75, SKS and AR15. I would not be surprised to see them introduce 12 and 20 gauge magazines for the Saiga shotguns in the coming year.