I've finished testing a few more DC drives, here are the auction listings -
These would be good for a DC motor on a wood lathe or other tool - they
won't work with an AC induction motor though.

Minarik DC SCR PWM variable speed drive SL3025A
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=3867732265

Minarik DC SCR adjustable variable speed drive 23001C
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=3867896394

Minarik DC SCR PWM variable speed drive XP10=115AC
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=3867906169
--
Bill
also check out http://www.wbnoble.com