ok, that is a standard P22 with a threaded barrel adapter on it. you should be able to remove the adapter and put a standard CA-spec thread protector on it and make like a standard CA-spec P22. the problem is that it is an off-roster version of the P22 and couldn't be transfered unless made SSE.
I'm not aware of a long barrel offered to make it dimensionally-compliant.
this one is rostered already,
