Use PCB design software to create the new reticle and then get photoplots made. Use the old faceplate as the back for the new reticle. The pcb design software will allow you to make very accurate thin lines. If photoplots seem too expensive you can try printing on clear overlay material. If you think the reticle + overlay is too thick, you could paint the back of the reticle or find a different backing.
Steve, you HAVE to be a Southerner at heart! When I moved South about 40 years back, I quickly learned some of the secrets of "talkin' Suthrin." #1: The law of the redundant adjective: always add an adjective before every noun. Example: a writing instrument is NOT just "a pen"; it's an "ink pen" so as not to be confused with the "pig pen." I never met anyone who said "ink pen" who didn't grow in te southern US.
I remember as far back when I was an apprentice in an instrument test lab, we had a guy who's job it was to re-calibrate moving coil meters for aircraft.
He would also turn the dial over or just re-paint as mhrackin suggested, then use a compass with an ink pen attached to re-draw the new scale. One thing he always did was inject various know signals then mark where the needle rested (i.e. calibrate the meter), he would then use those marks to accurately reproduce the scale markers (with the aid of a straight edge). He also hand wrote the scale values and they looked really good (good enough to put in aircraft in fact).
Could I suggest that you use the bigger meter for the minutes. Resolving 60 scale marks on a small dial might be difficult and most certainly harder to read.
I suspect this (AC) ammeter also has a removable rectifier in it; the clue is the "dead zone" between 0 and 2A, where the voltage across the shunt is below the band-gap voltage of the rectifier bridge. Looks to be actually 1.4 A, so assuming Si diodes, that tells me the shunt should be close to 1.0 ohms. Isn't it amazing how I can do the "Sherlock Ohms" thing from this far away? Thus my constaint complaint about the negelect of basic physics in today's EE curriculum.
@DrQuine: The new text was on several small spot labels that covered the old text. If you have access to an old lettering guide and a good fine point permanent pen that might also work well for small captions.
I think this option would be very low down my list of solutions -- I want every aspect of my projects to make the observer gasp "Wow -- that is amazing -- let me buy you a beer!" LOL