I'd use the armature wire from the generator for the alternator output, and connect the BAT and ARM wires together at the old regulator. You can either leave the old regulator in place and use it as a junction block, or gut it out and install a small fuse strip inside to power accessories. Don't go ape on alternator size- - - -a 55-60 amp should be plenty.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!