The tank arrived and I tried it out. It looks like the only way it will fit easily in a 64-65 would be to relocated the battery. So, I will probably stick with what I have for now.
fyi........ Frank McIntyre is the one that produces all the repro overflow bottles that everyone else sells. OPGI, TPP, YearOne, etc., etc. The going price is usually around $149. I doubt OPGI will sell many at $100 markup.