Peter
The tilt adjuster for the 8" scope is different from the 10" in diameter.
Bintel has it here for the eight inch
http://www.bintel.com.au/Accessories...oductview.aspx
Hope this helps but Al's collimation aid is the best thing since sliced bread for collimation and takes all the guess work out of it when used on a star.
I have astigmatism in my eyes which makes it difficult to judge a clean circle. ACA takes care of that and I've never had a problem since.
Hope this helps.
Allan