Hi Paul,
Sorry I didn't see your email till just now.
I never received much interest in Coypu-JVM, perhaps because I never tried to promote it in the Java community properly, or perhaps because there's such an established Selenium user base already.
For this reason, i've not looked at it in a while so perhaps it just needs bringing up to date with the latest webdriver.
Did you have any more success, or did you give up?
I'll take a look and try to get it up do date with both webdriver and the latest API changes to the .Net version (which is rather more popular and has moved forwards a little in the last year).
Cheers
Adrian