Ah, thanks Ken,
As for figuring out if your scope has good optics, first it is best if the optics are clean - the condition of the silvered surface isn't as critical to determining the quality of the figure, but of course if the silvered surface isn't too good, this will reduce the reflectivity of the mirror, and introduce a lot of scatter making the image "hazy" and with reduced contrast. This can be fixed though by re-silvering/re-aluminizing the mirror.
The figure of the mirror is what determines "quality". And the easiest and quickest way is by doing a star test. Seeing conditions really need to be very good in order to get the best evidence. Collimation is CRITICAL here too!!! Unless this is done properly, with the secondary mirror* looked at first and only then the primary mirror, then a star test is useless.
* To get the secondary mirror right, the easiest tool to use is the humble Cheshire eyepiece. Full collimation can be totally done by using a Cheshire, but a laser helps things with the primary mirror and tiny tweaks of the secondary. But remember, a laser alone will not get the secondary mirror right, and the secondary NEEDS to be looked at first before the primary.
Once the scope is properly collimated, and seeing conditions are stable, bring up a very bright star in the scope, and using a medium to high power eyepiece you defocus the image of the star by moving the drawtube in and out to produce a large "donut". A good set of optics will show an identical round and symmetrical donut with the eyepiece inside and outside of the focus point. Variations in the symmetry can indicate problems. This is why collimation needs to be spot on as a star test will also show any collimation errors! However, star testing also needs some understanding of what to look for. You can do a search for star testing to help you with this. Star testing is just one tool for gauging optical quality, and not comprehensive by itself. There's other bench-top ways to do this testing, and I'll leave it to others to add to this.
Alex.