This is unused. Sold my bike before retrofitting.
The series regulator retrofit has come up several times here on ROV and other motorcycle forums.
I am including the Triumph wiring harness that is commonly used for the retrofit, and a digital voltmeter. Also unused
Partzilla has the SH775BA listed for $190.99. https://www.partzilla.com/search?q=4012941&ui=typeahead
Yours for $110 shipped within USA.
I also have the following miscellaneous Vision parts available if you want them.
Rear exhaust seal
Rubber cushion for tank mount.
Air filter housing. Condition of filter unknown.
Custom tool for the carb synch adjust rod.
2 headless bolts. I used these to keep the side side case and its gasket aligned when re-installing.