Thanks to many here for your good advice. I don't have many "Before" pictures, but picture an ultra-cheapo chipboard vanity that looked liked it had been salvaged and then painted green, very plain 4x4 tile, vinyl flooring that was coming up, a scratched and chipped tub, and no fan. A simple "refresh" (tile, fixtures) turned into a major remodel due to significant rot because of a bad previous remodel (i.e. no vapor barrier behind tiles). I had to sister or replace new studs around the tub (while trying to retain the lath and plaster on the adjoining walls), and replace the floor. Despite that, it worked out great!

Here is a link that might be useful: Guest Bath