How intact are the detectors on these old meters?
I have a Director (also with the dome dimpled, yellowed, etc) but it compares closely with my Soligar Spot. On the other hand, I also have a Weston Master II that is about 3 stops off (less light detected).

My Soligar is dead on linear and I've been using it for 20 years, so I "trust" it.