Paula, If it were me, I would paint the chips on the Secondary with Flat Black paint/Marking pen and ignore the little scratch on the Primary. Stick the whole thing back together and try it out.
You can always replace the secondary down the track and the lack of light gathering by the scratch will be a tiny percentage of the whole Primary surface.
I'll bet it is a whole lot better than this old thing......
http://invaderxan.livejournal.com/95262.html
Good luck
Michael.