I'd imagine the reg/rec will be a standard part fitted to similar (spec and age) models... Perhaps the same as vfr400 or cbr400? Live Forever or Die Trying
Oh, just read your post about buying it. Where's it coming from? Hopefully will be here soon. If smudger has a spare you can use you will at least have the bike back on the road? Live Forever or Die Trying
FWIW if you source an early R6 rectifier or R125 item with the 5 spade connectors, you can simply reverse the Red / Black main feed wires around and its a fit and forget solution. I do most of my RVF's and NC's when they eventually fail (and they always do)
I could get one to you by tonight. Have two spares and Matt (Maffix) is popping mine later on and lives around the corner from you. They are plug and play. The ignition is two hex bolts-again Matt has them and would probably help you out too- another 5 minute fix. The bros is a great bike and hard to come by, fetching much more than what you are thinking. Don't sell-Fix