The easy answer was to send the turntable to VPI who were just great,
The VPI Tech moved the current arm base and installed a new black arm board under it to attach it and cover over the old 10" arm base holes. I had checked beforehand that they could do this, basically on my shipping the turntable base both ways and no other charge(s).
The VPI Tech also kindly did some undiscussed complimentary work: (1) cosmetic repair of two scratches on the base's black piano finish, (2) a replaced main platter spindle that the platter rests and spins on (it was just a bit wobbly) and (3) added lubricant to the new platter spindle. Wow!
The VPI 12" 3D arm with Reference wire I had already bought was then too big to turn fully on the pivot with the supplied screw on azimuth weights. Yep, smaller weights were needed. VPI kindly sent me two sets of different smaller azimuth weights for free. The smallest size weights work great.
So great service and then some....and the tricked out Classic 3 clearly sounds so much better - especially cleaner and more detailed aka more precise, smoother and a bigger soundstage!!! Very happy and thank you VPI :-)