The rear view mirror was fouled up on my Nash so I made a new gl***. I'm no expert but thought this may be helpful information. I bought two things, a small gl*** circle cutter and a larger one I modified. Larger one has a suction cup and I made a longer arm so with both I can cut from 1/2" to 40+". You'll need disposable gloves, eye protection, oil can, and rubber mat (dollar store), standard gl*** cutter and sandpaper or stone. Lots of gauges and flashlights have plastic lenses which I replace with gl***. To cut circles I lay rubber mat on cutter table, then gl*** piece square cut a little larger, then use old lens as guide to adjust diameter. Then drop of motor oil, very lightly make an oil circle. Now I can verify diameter is exact. Then make the cut. You gently press down as you turn one revolution, it makes a crisp sound as it scribes. Now I hold it, lightly tap with cutter on other side, you'll see the cut go all the way through gl***. Then I lay it on mat and hand cut line close to circle edge then snap off over trash can. With cutter slot or pliers work around circle. You really need a wet grinder (professional), but sandpaper or stone works ok for me. To make the odd shaped mirror I used a magic marker and old mirror as pattern. Then used large circle cutter adjusted for the same arc. The finished one matched original. Cutters can be ordered Amazon or eBay. Hope this helps someone.
The Jalopy Journal
