Well, eight years later and I actually have both; a new B3 Mk2 and a 1965 (or thereabouts) A100 which I imported myself and had tweaked to run on local 240V 50Hz current.  In my experience, every old Hammond is unique, and my A100 is a punchy but fairly mellow beast.  It's tone is far warmer, deeper and cleaner than the Mk2, but the keyboards are noisier,  and less refined to the touch.  If I could only have one, it would be the A100.