Graham
I used to have a VC200L (late 1990’s) and the Vixen F6.4 Reducer (original model).
One end (telescope side) of the F6.4 Reducer simply screwed into the 60mm thread of the VC200L drawtube and I then used a Vixen 60mm Wide Adapter on the other (camera) end which offered a T-Ring for my Pentax 35mm SLR.
My Astro Shop has these on their website.
Vixen Wide Photo Adaptor 60mm - General Type ($62)
Vixen Wide Photo Adaptor 60mm - Canon EOS ($69.95)
Is it one of these that you are looking for?
Cheers
Dennis