I once owned a Gamo repeater; CO2-powered, detachable magazine (rotary, I think?), two-piece wood stock, .177-caliber, adult-sized, fairly sleek and nicely styled. It was a non-PAL gun (non-FAC at the time), sub-450fps, and decently accurate. Worked well for a number of years, sold it without much if any monetary loss.
I certainly can't recall the exact model name, so don't know if it's your gun or not without pictures...hint, hint...