Spike, I guess it depends on where it's located, be it in the front or the side, under a cabinet, bet or gaucho. You'll need to remove whatever is in the way, remove the tank and find one the right size with the inlet style/location you want. You may need to reuse the pipe and cap from your old tank. Likely there will be wood rot in the floor under the tank, at least every one I've ever removed either the tank has leaked or where the fill tube exits the trailer has leaked over the years. Take pictures once you have it!
Scott & Megan
VAC LIBRARIAN WBCCI 8671
1963 Safari from the 1963-64 Around the World Caravan