JD2439975, I agree with your findings, I have had exactly the same probs as yourself. The teflon strip is a good idea to stop the misalignment issue - I'll have to track some down and see how it goes
Attached are a few pics of the mounting on my scope - because there appears to be no focuser for a 10" scope the 8" one has to be used, I added some weather proofing tape to fill the gaps because of the different diameter of the focuser and tube.
Grahame.