I'll add my info to this post (yes, I'm a hypocrite). Anyway...
First off, Tony is a great guy to deal with.
I sent out my Saiga 11/16 and Pat (Oregon Research Labs) got it back 1/10 or so.
His work is actually very fast. But he still has to wait on Form 2s and crap like that to so the SBS things. As a result he tends to do them in batches. Still, figure 4-6 weeks total.
I will say, One option you HAVE to spring for is the G3 sights. Very very nice.
The 12.5" was shooting birdshot about 1.5' wide at 15 yards. Slugs were dead on. Offhand I was putting a nice cloverleaf pattern. Obviously, out of a barrel that short, slugs do make a rather large fireball.
The TiG welding Tony does is very good. The only issue I was having with the Shotty was it not fully ejecting on the tight gas setting. Of course it also had ZERO lube in it. Quite honestly, the regulator plug probably needs to be shaved just a bit.