The alternator. A company who makes pattern electrics for bikes shows the same unit for a number of bikes.
http://www.electrexworld.co.uk/cgi-bin/ss000001.pl?page=search&SS=BMW+F650&PR=-1&TB=A
the one at the top for instance shows as suitable for:
Honda: VF700C, VFR700, NR750, VF750, VFR750, VF1000F/F2, VF1000R, VF1100C V65
APRILIA: Pegaso 650 BMW: F650*
It's very common for parts to be swappable like this as manufacturers seek to drive down costs, bespoke parts are a lot rarer than you may think, I "think" the switch gear on the Funduro is the same as fitted to CBR600F's of the time as well.
I worked for Kawasaki in the 80's and had a K100RS, the starter motor brushes failed on it, turns out the starter motor was the same as the Kawasaki ones (Nippon Denso if I recall correctly) and the lads in the workshop popped a set of Kawasaki ones in for me

Ancillary parts are sourced from various manufacturers and they will supply similar items to a few of the bike companies. Generally connectors may be different but they can be transferred over
The alternative one in the list from electrexworld shows as compat with
Fits: | |
HONDA: | VLX400 Shadow, VT400C Shadow, VT500C Shadow, VT500E/FT, VLX600 Shadow, VT600C Shadow, XL600V Transalp, NX650 Dominator, XRV750 Africa Twin |
SUZUKI: | VS600/700/750/800 Intruder |
YAMAHA: | XZ550, SZR660, XV700, TDM850, XV1000 Virago, XV1100
XV750SE* Please check the measurments on your existing part as our generator may not fit |
BMW: | F650 |
MUZ: | 600 Scorpion |