If the decals don’t work out for you…
I purchased a new assembly of numbers when I refurbished the speedo head on my ‘46. It’s held immobile at all zeros with a plastic clip which you pull out AFTER you install the new assembly. If you remove the plastic clip before the assembly is securely in the head, you spend the rest of your life getting it reset back to all zeros (don’t ask how I know that).
I’m of average mechanical skill and am very pleased with the results.
Greg