A 295/50/15 is about 26.6" tall, and 11.6" wide. I had that tire on a 10" rim and wouldn't go any narrower than that. People have, but it doesn't look right. Since you have 10" Campys, they're the right width for the 295.
295/50/15 is made in several brands. Here's a tire rack link to the choices:
http://www.tirerack.com/tires/Compare1.jsp?width=295%2F...unFlat=All&x=44&y=11
Michael
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