So what are the possibilities to install an HD motor into the "five-speeder", using a properly machined adapter plate? It's been done before, with the Liberty ACE.
Better yet, (with the forbearance of all the piston heads here), I would envision a gutted out X-Wedge or HD Evo V-Twin, with an electric motor in place of the cushion drive. Automatic paddle shift transmission eliminating the Mazda box; topped off with a Gold Wing rear end to get rid of the whine from the bevel box. Removal of the fuel tanks would make plenty of room for batteries.
For the ultimate in drama, one could check with the Low Rider crowd to source some powerful amplifiers and speakers, and produce just the right kind of V-twin deep, throaty growl electronically tied in to the transmission. That should brilliantly round out the whole enchilada.
The name for the machine? Volta 3 (Trade mark registry in progress).
Tom