The last time I took a bath, I think I filled the tub with about 6 inches of water. BIG mistake! When this whale-size fanny sat down, it caused a tidal wave of the Perfect Storm proportions! Our fiberglass tub was so uncomfortable, I think I got more kinks in my neck from the bath. When it was time to get out, I had the presence of mind to let out the water ... what little water was left in the tub! I don't remember how I got out. I tend to block out traumatic experiences. I don't think I could even get into a claw foot tub now! I have trouble lifting my Bozo The Clown-size feet into a small tub. My favorite thing is to sit on my shower bench, put my shower head with the long hose on fire hose setting and just massage my shoulders, arms, legs and feet with it. I have been known to fall asleep in the shower as a result of it. But then ... I fall asleep at my computer at work so that doesn't mean much! Thanks for the hilarious story, toomuch. Luckily Bob is asleep and not giving me strange looks for laughing out loud.

Manufacturers only make things that they can sell. If they made a 58" tub they might only sell one, and that would be to your. If you cannot use a 60" tub, the next smaller commercial one is 54". Anything between the two measurements would have to be plastic and made locally. After this you can try Here is a link that might be useful: Walk in Bathtubs

To all responders - many thanks for the comments and suggestions. Was able to open access door at plumbing end of tub and was able to see steel mesh and clumps of plaster below tub rim on exterior wall but no sign of studs - so I assume that plaster with mesh support is also behind wall tiles. This would explain erratic readings with stud finder. Exterior wall is brick - not sure if stud finder will give reliable readings through brick but will give it a try. If so will give me some general idea where studs might be.

The overwhelming majority of demographics for your complex would prefer a great shower versus a mediocre tub/shower. Aging people who want to age in place need a shower - and as large as possible because stepping over a tub becomes increasingly problematic. Design with both function (bench and as many grab bars as possible to be reachable anywhere in the shower). While many older people are nimble up to a certain point, there are also periods when they might not be able to bathe and among my senior friends many have given up baths even if they previously enjoyed them because of difficulty of getting up from the tub. While you might lose a buyer who absolutely demands a tub in the master, the greater number will appreciate a great shower. And, if someone really wants a tub experience as critical, chances are they would prefer a larger soaking experience versus a tub/shower combo which doesn't provide the best experience for bathing or showering.