I have an Telescopics Newtonian mirror. I believe it is an f6 might be f7. This mirror has sat in the original shipping box for many years. The coating is PERFECT. As I recall when I checked it on arrival it was within 1/8 wave (possible 1/16th). Telescopics has been out of bussiness for quite a while but had an excellant reputation for making 1st class mirrors.
I'm not sure what this is worth these days so,I will sell to the highest bid I recieve by Oct 17th. I don't think you will be disappointed with this mirror.