When I was sorting out the parts originally, I managed to drop the Talbot mirror.  It didn't hurt the metal part, but the mirror did break.  So that was one of the things to get replaced.

I used a circle glass cutter that my Dad had kept from the hardware store in the mid 60s.  I inherited it in the mid 90s and have never had a need for it since.  I did point out to my wife (who thinks I'm a pack rat, for good reason) that I was using a tool that I've kept for 10 years.  It's good to make sure that they appreciate why men keep accumulating tools.

Pictures of mirrors are self defeating.  The camera want to focus on the reflection plus you have to worry what is in the reflection.  The next issue was breaking the outside part and leaving the circular part intact.  It took 4 tries.  Here's the third:

At least it fit in the frame.  I figured out that I could trim the edges off with four straight cuts.  Then 1/4 of the circle would break cleanly to the next edge.  Finally I got  one cut out in one piece.

I used the wet grinder to finish up the edges where the straight and circular cuts didn't break cleanly.  Then it was off to the buffer to polish up the chrome.  A little silicone rubber was used to cement the mirror to the body.  Now I'm back to where I was when I dropped it (maybe a little ahead since its been taken apart, cleaned, polished and ready to install).

Roy Goodwin emailed me these tips for cutting circular pieces of glass (or glass in general):

1. Brush a lubricant like kerosene onto where the cut is going or if using a handheld cutter just dip it into the kerosene. This helps keep the cutter roller from sticking & thus leaving skips in the score. It also helps make the score better. I don't fully understand the physics of that, but from having run a glass & mirror shop for 12 years, I know it's true.

2. For circles or curved cuts -- tap the scored glass or mirror on the BACK side (opposite the side that's been scored) to start the cracking and then continue on around until it's completely cracked along the score. THEN start cutting away pieces on the outside.

3. You might want to see if you can find some bronze mirror -- it's MUCH better at night since it reduces the glare. If you can find one way mirror in double or single strength it would be even better, but that can be VERY hard to find.

I hope to not have to cut any more circular pieces of mirror (as it means I broke one), but I'll most certainly try these tips out if I ever do.