Is it a Colt factory SBR or did you or a manufacturer file the form? By the two roll pins for the magwell adapter and the size of the fire control pins, I'm guessing that is a late model lower?
SBRs and Cans are so difficult to resell. Unless you can find someone in your state, the double stamp can be a deal breaker. If you want to take the hit for the extra stamp. But who wants to loose an extra $400 ($200 you paid originally and $200 to ship out of state).
I have an idea for the extra YHM pistol FF rail. TROS
http://www.trosusa.com/ makes a five inch 3-lug M16/9 barrel. With that little pistol rail, you would only have a can or a HK flash hider sticking out. I had one. The barrel shot great. A 5" barrel will keep most all of the 147 gr ammo subsonic. I've had 9" or 10" barrels that the 147 gr 9mm would go supersonic. That kind of defeats the purpose of the can, IMHO. I made a local deal on the complete upper with a Gemtech Raptor can, when I was hard up for some cash. I had bought the can local, and sold it local, plus the money I got for the upper (I found the parts over time at good prices and sold for the extra $200 I had in the stamp). Unless you do the same thing, it will hurt to sell your SBR 9mm Colt.
Scott