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?
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.
I'm not sure but I would think it would change your spindle to pivot distance which would make proper cartridge alignment impossible
I am certainly aware that changing wand lengths will change cartridge alignment. I will be mounting on a custom plinth SP102, with an arm mount that extends and rotates, so I can change the pivot distance easily. the wands will use different cartridges. My question is more on the line of Bpoletti's post, where the question is whether there is difference in pivot structure. VPI arm wands come up fairly often in the used arena, so I want to see if my 10.5i base will accept a 12.6 wand, for instance.
When you call VPI, make sure you have the exact model of arm wand and the base(s) on which you intend to mount such arm wand.