Hi Lionel, Welcome to the forum. What part of Ontario are you in? I'm down in the SW near Sarnia. I've just started a reno of a 77 Trillium 1300 also. I was given it 6 years ago and almost sold it this spring but once I started cleaning it up to sell, I decided to keep it and fix it up.
It is interesting to see photos of yours to compare to what may have been in mine. I thought there may have been a furnace in mine at one time as there is a big hole beneath my closet with no door. But there is no vent on the outside of the trailer for it.
I still have a converter in mine but no deep cell battery
yet. There is a cupboard beneath the sink and then the converter below that. I just have an icebox frig but there is an electrical
outlet behind it and I would like to get a working frig eventually.
Mine is already in pretty good condition. No structural or major repairs to make. But both faucetts didn't work and the gravity water tank and all water lines were pretty grungy. So I removed everything and just put back in a city water system. I decided I'd rather have the storage room than the water tank.
I installed a household faucett, meant for a bar sink and just capped off the second line that would have been for hot water. I installed it in the middle hole that the pump faucett would have been in. It turned out rather nice, I think!
I tore out the old carpet that was in there and have installed sheet vinyl flooring. I've sandblasted and painted the wheelrims and got new tires
and have replaced the out of date propane
tank. Next on the list is recovering the cushions and installing some kind of new window coverings. And installing a new powered roof vent.