Hello everyone. Pardon my ignorance on the subject of telescopes. I have never owned one and know nothing of the inner workings of one. While cleaning out my in-law's house, I came across a telescope in the attic. I thought it would be interesting to clean it up & get it working. I believe it is missing some parts. It is a SPI Astronomical Telescope. No. 521N F=800mm. D=60mm. Would anyone have an owner's manual and/or a parts list for this particular telescope. I would appreciate any help. Thanks, Charley.