What is the best product to fill in the numbers on a bezel when they become patchy? It’s a plain steel bezel with black numbers.
I suspect enamel paint from the hobby shop would work fine, but this is just based on similar types of projects I've done. Not this specific type of bezel.
I have a Dodane which John Senior redid the bezel on, many years ago. Now you’ve said it the ink does ring a bell.
Nail varnish does wonders, I used to use it on pantographed campagnolo parts. Wipe the excess varnish away with nail polish remover without acetone.