When you check the wiring, you may find a heavy brown wire leading from the starter relay on the nearside bulkhead that disappears behind the dash and reappears on the offside at the fuse box. The fusebox (if original) will only have 3 or 4 fuses fitted. Check the brown wire near the starter relay has a circuit breaker or fusible link fitted. If not, fit one soonest. You might find a photo or two on here of the modifications I did to my '76 wiring in that area.
Most of all, have fun with the car. 4 seater X-flow prices have risen quite dramatically since I thought about looking a few years ago.