Got it, I think. After a long and fruitless search on my own, the answer was found on the internet, by another.
I called my library's trusty Just Ask line, and was told that foot fetishism is called RETIFISM. It is one of the
paraphilias (sexual deviances). So, I guess a foot-fetishist would be a retifist. I'm a bit busy, so I haven't gone to the site, but here it is:
http://www.mhsource.com/expert/exp1050399d.html