When I bought my 77 bus, it came with an incorrect and non-working clock. Someone had put a smaller VDO clock in place with what looked like a home-made adapter to fill the hole.
I just had to correct it!
Watching for correct black faced VDO Quarz clocks that are in working condition I realized they are not insignificant in cost. Other projects on the bus got priority, but the incorrect clock just bugged me.
I found one that was correct and the seller sent me a video of it working, so even though it looked filthy, I thought his price was fair.
Photos below help tell the story.
When it arrived, sure enough, it was really dirty. The dirt on the class and the condition of the outer bezel holding the glass to the body was just cruddy. Probably had not been in a bus in years.
First step was to gently use screwdrivers and fold back the flange holding the bezel to the main clock body. Glass was dirty on both sides.
I was able to wash off the big globs of dirt with running water and then gently clean the glass. That was simple. Although the bezel does not show when installed in the bus, I noticed it was made of brass. Out came the 0000 steel wool and Brasso. It really made a big difference. I also gently cleaned the clock face and then used Q-tips and 409 cleaner on the clock hands.
I am happy with the result. Installation went smoothly and the clock keeps great time!