I called the number and they honored my warranty claim against the Double tap unit wsealing rings (7444578) for my Eheim Professional II which they recognized as defective back in 2001, agreeing after a tango of words to send a replacement, free of charge!
(Well OK, I did agree to pay shipping but that was 12 bucks - now that I think about it... That's pretty high but still much lower than buying one outright.)
Thanks for the number!
I am still however nervous to place the unit under my tank again as the last 'soak' was unwelcomed and is quite hard to forget