a
T-minus adaptor, as Daniel has suggested, is supposed to be "an inch shorter" than usual t-ring-t-adapter solutions. that's how far the specification re length goes ...
I hope that this one part does not require a t-ring but screws directly into the lens mount and fits into focuser barrel?... I hope. daniel? did you buy this part?
it's a 2" solution; my current rack&pinion focuser is 1.25".
now I need to find a 2" focuser "low profile" which is within the 6.8cm range of the focal point and still allows for the "1 inch shorter than usual t-minus-adaptor".
or move the mirror....
is that correct?