Have one where this is done might be nice to touch it up where it is gone?
I just use model paint, daub it and and a wipe over the top to leave the filled lettering.
You can still get the proper white silver or gold lettering inlay paint from Forsters an American company https://www.forsterproducts.com/prod...t-single-pack/ The base product is a resin that goes off which is very durable. All you do is degrease the gun lettering with acetone, mix the resin with powered gold silver white, smear in and remove excess with a solvent. You could use a paint like 2k or acetone in very small amounts and use what ever colour you want, thats all it is, gold silver or white does enhance a new blued gun especially gold.
Another vote for Tipex.......
tipex does the job nicely