Adapting Sinar Binocular reflex finder to a Whole Plate or 8x10"?

Has anyone ever tried to do this?

To me, 3 modifications have to be done to the Sinar finder:

1. Longer focal length eyepiece lenses since they will be farther away from the GG than on a 4x5 Sinar. Think I can easily acquire them.

2. Extended front end of the finder for the larger formats. Metalsmith friend advised me to go the route of a "plastic" extender, which would be more easy to fabricate, or find someone who could fabricate the extender out of aluminum.

3. Way of attaching it to the rear of the camera. This think the easiest part to figure out and fabricate.

VIEWCAMERA Magazine once had a single page article on the fabrication of a reflex finder for an 11x14 View camera. Will have to find it once again... maybe the simplest and most direct route to go in the end?