ok, I finally found the hard drive that had the photos on it. If I find the rest of the photos I took while restoring and painting the safe, I'll make an entire thread dedicated to that project.
Click the pics for bigger images!I will say that of all the things I did to restore the old Protectall safe (back in 2012), repainting the dial was the biggest pain the ass ever. I painted it and stripped it half a dozen times before I was happy with the way it looked.
Having done it that many times, I learned two things were important, removing as much of the old paint from the numbers and lines, and letting the base black coat be completely dry before rushing to paint the lines and numbers.
Let's start with the safe, as it was when I first brought it home. It's a 1947 Protectall I purchased on craigslist for $100 bucks. (the other locks are for scale

At some point or another I decided it would be a fun project to strip the safe and paint it, and as I was close to finishing, I realized the dial would look very ratty compared to the fresh new paint, so I thought some model paint would do the trick to quickly paint the numbers white again. boy was I wrong.

Without any sanding or removing old paint from grooves, I simply used black Testors model paint for the dial, and white Testors model paint for the numbers and lines, and the results were awful.

Up next I decided to sand and scrape and get as close to the metal as possible. No matter how hard i tried, I was not able to get all of the old original black paint off the dial.
I used dental tools, push pins, and some gun cleaning brushes. It is super important to scrape the lines and numbers as deep and as well as you can, the new white paint needs a place to go and it needs to be thick enough to last for years to come.

As you can see there are plenty of nooks and crannies to scrape clean:

I ended up using Rust-Oleum automotive engine block high heat enamel spray paint to paint the dial black. In order for the paint not to run, I actually hung the dial from the basement ceiling on a string tied to the spindle. The YALE on the dial faced down towards the floor and I sprayed upwards, walking around under neath the dial, waiting a few minutes between coats. One or two of the half dozen times I went to fast and too heavy and paint started dripping and running, which ended in me stripping the dial again back to metal and starting over.
Eventually I figured out to do a handful of coats and be patient and wait for them to air dry, then in the over she went for a couple hours. I don't remember the temperature I used, but 200 F seems to be sticking out to me for some reason.

The dial was allowed to cool off completely before attempting to paint the numbers and lines with white paint.
Here is is out of the oven

another angle, see how deep the lines are? plenty of room for some white paint! all the prep work was well worth it.

so I had that white Testors model paint, and wanted to put it to good use still. Now that the base paint was totally dry I could fill in the letters and numbers and lines and not have everything smear together, which happened on one of the times I redid the dial. After brushing in the paint, I used a little cloth to wipe the flat surface of the dial, as you can see it left smears behind, I later figured out a way to stop that from happening.

other than the smears, it's starting to come together

see how the YALE is starting to look sharper and cleaner? Instead of a dry cloth, I actually used some water on the cloth to pick up more of the surface paint left behind. The black base of the dial was 100% dry from the oven and never smeared or bled during the process of painting the numbers and letters white.

I found that painting about 10 numbers wide on the dial was the ideal speed. As you can see the white paint is runny, and several applications are required to fill the numbers and lines. All that excess paint is from before I wipe it away with the wet cloth.

ok, here we are, the dial is done. It's not perfect but looks a lot better than when we started.

Here is the dial mounted back on the painted safe, I'm very happy with how it came out!
One thing I never did was to five the entire dial a coat of clear coat to seal everything in. After 4 years since painting the dial, and opening the safe about once a week, I have not noticed any wear at all from the time it was painted.

Hope this helps others who want to try repainting the lines and numbers on their old combination safe dial.
Squelchtone