I knew that the light would need to be straightened before or after a diagonal. A diagonal has only a short distance to cover after a standard focuser so the path could be short enough to use a diagonal on a Newtonian while afterwards other barlow lenses could be used to provide an extended point. (albeit small)
The lense used Mersenne to straighten the path was he kind of thing I was looking for, but still haven't been able to locate anything as yet.
Thanks for the information, am still interested in this method of observing as it intreged me when watching the movie. I myself prefer to stand when observing, although strange I have multiple injuries that dont make it easy for me to stand. Maybe it is what I am accustomed to over the years standing up while electronic servicing.
Even if it become to difficult or near impossible then I had fun trying.
