Jim;
I agree about the suppliers of spares...where would we be without them?
Your experience with slave cylinder is typical...that is, about a year of service after a "rebuid"...but even with a new slave, I still suggest an O'ring on the piston...and changing to silicon fluid. Suggested reading:
http://sw-em.com/hydraulic_clutch_tech_article.htm
Cheers from Connecticut!