Geoff, here is how to take the eyecup off. I got this from a fellow Cloudy Nighter, (Amalia). It's really easy after you try it once. To take it off , use your nail ,( if you have any), and gently pull the rubber up from underneath. Here is a German link, with pics. Here is an online translator below the first link as well.
After you pull the rubber eyecup off, make sure to unscrew the aluminum *DOWN* away from the eyelens and toward the table or whatever the EP is sitting on when you do this.
http://www.rudolf-reiser.de/astro_tech_pentaxxl.html
http://www.worldlingo.com/en/website...ranslator.html
I hope this helps...and YES I am going to try that Teflon tape that plumbers use
Thanks for the tip!!!
In case you were ever wondering, a lot of people take the rubber eyecups off to use two Pentax XL's for Binoviewing.
-Mark