Okay thank you, the one that I am looking at tomorrow has 42K miles so fitting the 775 will be good preventative maintenance The mosfet seem to be way more popular but the series type 775 makes the stator run cooler, I don't think many bikes had sufficient oil flow to make the stator live forever with a shunt type regulator saturating it's coils to regulate voltage.
From what I have seen online, the wiring will need some modification to make any of the more modern Regulators fit, I think I have the plugs in a "safe place" from Eastern Beaver... Plenty to have a go at.
As for my current bike, it's too good for me, so good I find it bland, the VFR from sound alone offers character.