a 75 gallon tank should be OK
A word of caution: The age of the home is no gaurantee that it was constructed properly.
I have remodeled a number of old homes and have found many instances of , shall we say, interesting construction techniques (poorly done balloon framing comes to mind).
yeah im just going to put it on an outside wall just to be safe. i now have 2 tanks in my living room. i have a 35 and a 29 gal. in between them i have an entertainment center with my big screen tv. i have no creeks or nothing when i walk by them. my living room looks awesome though. i wish i had room for the 75 in there but i'll putt it in dining room. yeah this house seems well built so i should be fine.