G'day Logan, for the 80mm F5 finder, no machining:
- 100mm WO Guidescope rings.
- Objective lens and cell from SurplusShed
- Telescope body and dew shield are standard plumbing fittings plus a 50mm drawtube from a GSO Crayford forcuser, hose clamp and 1.25" reducer.
- 1.25" UO RACI 90 degree diagonal
- 32mm
Celestron Plossel circa mid 1990's with added cross hairs.
Grant, at F5, not much point in using a 40mm eyepiece due exit pupil size, suggest 32mm or shorter.