Review:40 year old Odyssey1 Dobsonian Telescope (13.1" mirror) by Coulter Optical

I purchased this used as at least the 3rd owner. Odyssey 1 (Introduced May 1980) Coulter Optical Co Idyllwild, CA 92349 (714) 659-4621 Focal Length: 1498.6mm (59") Mirror Diameter: 13.1" (Area: 134.78 Sq/In) Obscuration Diameter: 3.1" (area: 7.54 sq/in, Area loss: 5.6%) (Diameter loss = 24%, Apparent Diameter: 12.72") Native f/4.5 (f/11.8 with an 5" dia off axis aperature stop) Daws Limit: 0.35 sec/arc Limiting Magnitude = 15.6 Base weight: 52.8lbs Tube Weight: 56.3lbs (with added counterweight) The finderscope & finderscope mount were not stock, but I believe everything else is original. (Although possibly the top of tube cover was also aftermarket, it's just a piece of aluminum sheet metal cut in a circle with tabs bent over and taped with dried out duck tape which I removed and replaced with white gaffers tape.)