Years ago I was inspecting G62 engines after a race..Most showed about 110 lbs on the compression gauge when spun by an electric starter..One showed 150...when I got home I tested mine, got 110, put some 30 wt oil in the spark plug hole, got 150..depends on how well the rings are seated in the bore......
A Q50 with a thick base gasket will lose 500 or more rpm compared to a very thin base gasket, one that almost allows the piston to touch the top of the cylinder....