I think different generations of JMW arms sometimes use a different pivot structure. I don't think my original JMW-12 would fit on a modern base. Or at least so I've been told.
vpi JMW arm lengths
Can the various VPI JMW tonearm wands be used on various bases. I know there are different lengths, such as 9". 10", 10.5" and 12, 12.5, 12.6 1nd 12.7 models. but can you substitute a 12" arm, for instance, on a 10" base? the VPI seems to use similar pivot structures, and you can buy the wands separately, so is it just a matter of putting a 12" wand on a 10" base, or are the actual pivots incompatible? Or, if its possible to do with only some bases or arms, is there a source of which are compatible?