I started work on this scope in 1976 after completing my 6" RFT. I ground and polished the mirror from a pyrex kit that my father purchased for me from Chicago Adler Planatarium.
I was able to get the mirror to a perfect sphere at one point, but all of my attempts to parabolize it failed due to my lack of patience and not knowing what I was doing. Discouraged, I put the almost completed mirror in a cardboard box and forgot about it for 22 years. Last year (1998) I got interested in telescope building again and decided to finish the darn thing. I bought a kit from Willmann-Bell to complete the task as I had long since lost the cerium oxide polish and the pitch lap had fallen to pieces.
Not an American Airlines Happy Meal!
With the kit I was able to parabolize the mirror as well as turn the old tool into an f/5.2 mirror. By the time I completed both of the mirrors there was still enough abrasive left over to complete a 6" mirror except I had used all of the pitch up.
After a lot or horsing around I was able to get the mirror quality better than a 1/10th of a wavelength of light. It was a lot of fun parabolizing it and it's nice to know I'm better at somethings than I was 22 years ago.
Click Here to see the scope I made with the tool.