We have a fiberglass, one-piece tub/shower surround from the 70's that was ugly from the day it was put in. (To those few who like avacado green, I apologize.) It also has some plumbing issues (as in my recent other post.) If we replace it, we need to have another tub/shower combo. It fills the end of a very small bath, and we can't afford to move the walls. Here's the problem: Wall to wall across the front of it is 59 1/2 inches. Standard tubs are 5', right? What are the tolerances on that? Would a standard size fit there, or are they actually 60 inches? If I have to buy an off-size, where do I find one at a decent price?