If you're having electrical problems, I have my 1964-68 electrical diagram book out of storage, so I can get you diagrams if you need any.
Nice wagon. I like it a lot. My father had an almost identical wagon. Same color except the roof was white. I think the interior was green but can't remember and I spent a lot of time riding and driving it. He loved that car. It had the 390 and he towed a heavy 24' Scamper trailer across Canada (from Southern Alberta), and several states, and many trips to the interior of BC. The only issue he ever had with it was with the transmission once. He had it serviced regularly, it was his baby. The last any of the family saw, it was being used by a house painter to haul his materials around and was looking pretty sad. Glad he never saw it like that.