Before signing off tonight, I might take a stab at this.
Firstly:Make sure the battery terminals are clean and tight.
Make sure all ground straps are good. The 25 amp regulator is grounded via jumpers that go across the mounting screws.
The 25 amp generator has a separate regulator mounted on the firewall, big black box with fins. It can be adjusted by first removing the cover and then, using a small screwdriver, turning the small potentiometer on the very top of the circuit board. There are two, I think it's the one on the right as you are facing them.
The 60 amp alternator has a built-in regulator. It is adjusted by first removing a small pipe plug on the housing to gain access to the trimmer pot. It's near the wire terminals. The housing should be marked accordingly.
The dash bat/gen gauge can be useful if calibrated correctly. Best to put a DVM on the battery terminals, though.