Yeah I was worried about that, it probably would be best if I would save this project for latter. The 6" Dob was given to me by my uncle, it was made by his friend... who had left it in storage for many years without a cover

So there was a VERY thick layer of dust on the mirror. The coatings seemed fine though so we carefully cleaned it off. The biggest problem was it didn't have a focuser, just a drop in tube