The carbines were made between 77 and 85, I haven't checked the exact year for mine yet. Its a regular SP1, as far as I can tell.
The grip isn't proper, the guy I bought it from is CF like me, and he used to have the rifle serviced by Army weapons techs, so it could be a grip from a C7. I'm not to concerned about that. I was thinking of an A1 upper, but that would be it.