It would be interesting to try with a FR. They normally shorten the distance required to reach focus. Using the Mogg 1.25" reducer requires just over an inch of extra in focus compared to without the adapter and using the extension tube needs something like an extra 2.5 to 3" of infocus. Wonder what that WO 0.8 FR would do
How does it go with the SBIG and filter wheel Dennis? Reacon it will reach focus without the diagonal?