Cotty, Here are a few sites to check for info on M42 lenses. The first three are Pentax (thanks to Dario for AOHC). Peter Jonkman's spotmatic site has been offline for a while (I hope it reappears soon). The other sites cover other M42 lenses, and there are many more not cited here.
http://www.aohc.it/lense.htm http://www.m-fortytwo.info/ http://spotmatic.web-page.net/ http://captjack.exaktaphile.com/LENSPAGE.htm http://people.freenet.de/stauber/mamiya-nc/m42_czj_20_2.8.htm http://www.gate.net/%7Ehifisapi/lens1.htm http://www.praktica-collector.de/ http://www.praktica-users.com/lens/mlenses.html http://www.praktina.com/ Jim www.jcolwell.ca
