1976 Scamp fuel gauge problems

I've replaced both the speedometer and the fuel gauge, and now the speedometer works, but is about five high. The fuel gauge is still dead, but I know it's a working gauge. I also replaced the regulator with a known working one, but the back of the circuit board is well corroded and the pins are separating, so I'm thinking I'm gonna have to replace that too. The cluster I bought is for a 72 and not a 76, so I can't use that being the layout for the ammeter is different. Anyone know where I can get one for a 76 for cheap? Thanks.