Hope you get all your options sorted out chubbychaser! I largely avoid all that angst by having a rubbish eye for detail and just putting these things together based on what I like the look of, rather than whether it's historically accurate or not.
Meanwhile, on my project... Small steps... Forwards and then back again.
I used water-soluble oil paint to repaint the missing lume plots on the dial. The consistency of the mixing medium seemed spot-on to get the right flow. I used a fine oiler to apply the paint - it went on nicely and looked pretty good (didn't take any pics tho... d'oh). I had to leave it for a couple of days to dry, and it dried very glossy. So I then used watercolours to try to give it a similar appearance to the other lume plots. But that didn't fix the glossiness of the oil painted plots, and in the process of using the watercolour on top, the oil medium separated and seeped onto the dial, making a horrible mess. I then made things worse by attempting to fix the problem with brush-on matt lacquer, which a) didn't fix the glossy lume, and b) reacted badly with the lacquer layer on the dial, making it horribly patchy.
So this morning - in a sort of "do or die" attempt - I gave the dial a coat of matt lacquer spray, to try and cover over the leaked oil and damaged lacquer... and blow me down, it worked! Well, it worked on the dial surface really nicely - but the lume plots stayed stubbornly glossy.
What I need to do next is go over the two lume plots again with a slightly darker, completely matt medium. Gouache (opaque watercolour paint) would be perfect. But a covid-shaped spanner got thrown in the works, as I couldn't find any gouache, and couldn't just pop out to the art shop to buy some.
So I ordered some gouache online, gave up on watches for the day, played some more of The Division 2 and went for a walk.
Happy Easter Lockdown everyone!