I wouldn't spray carb or brake cleaner on anything plastic----or laquer thinner either,it'll either melt it,or make it cloudy and sticky,and ruin it...
I wrecked a dash cluster trying to use those 2 things to "clean" it..
You could try using some baking soda and vinegar in a paste and rub it in with a towel,or toothpaste,maybe rubbing compund ,to remove the yellowed stain--if its the plastic itself,it'll be unlikely to be removed though,its probably "burnt" from the heat of the bulb..
The battery powered clock mechanism's can be had at most hobby and department stores for about 5 bucks..maybe you could transplant the guts from an old 110V house clock into it too...
I cringe when I think of all the neat clocks,display signs and other counter trinkets I helped toss into dumpsters at the many parts stores I worked at over the years...probably threw a few thousand bucks away--they could have been mine,had I only taken them..
One store I worked at was in the process of moving to a brand new building a few miles from the old original location,and they had me tossing brand new superior mag wheels,headers for straight sixes,and floor shifters from 1970's displays that were all covered with pigeon crap in the attic into a dumpster 40 feet down,in the parking lot...
A friend of mine who worked in a tire shop for nearly 20 years was offered anything he wanted in the building when it was sold...he only took a few items,one was a large ash tray with a B.F. Goodrich tire around it that sat on the desk in the office for decades...not long ago someone offered him 400 bucks for it--so he took it...maybe he should have researched its actual worth first though,I bet it was worth more,judging by how anxious the guy wanting to buy it was...
I took home a whole "wall" of brand new 8 track AM-FM stereos and some other trinkets from that old store,but the board of health inspector kicked us out of the building--we didn't have proper "haz-mat" suits and he said the bird droppings could prove fatal,so my boss had to hire a legit company to clean out the place--and none of us were allowed to keep any of the merchandise,after they took over..
