Hello CarteBlanche. Those older Terry's were very much the same as the Prowler's. I have a '84 Prowler, and about only differences were exterior door placements and interior plans, but pretty much same as build.
Unfortunately, my Prowler was remodeled/restored by PO and they changed out all the electrical, new stud 2x4 front, rear and roof support, new insulation and replacing the stock invertor circuit w/ new system for plug and go, so I as new owner don't need to check whether it's 12v or 110 hookup---it's all automatic now. So sorry I can't help much. Good luck.
I will say, if it's not been changed out or destroyed. You will find TT info on a decal in cabinet door or closet area to give you some idea about what you have as model, build date and such.
Del & Jerre w/Isis our English Bull Terrier
The Cougar's Den
1984 Fleetwood Prowler "E"