More than likely it is a digitized personal font from the original gilders lettering types. Having done quite a few firetrucks for a dealer down south here and communucating with quite a few "Firetruck gold men" over the years, I can assure you it was common practice as soon as dealers started wanting and calling for signgold many gilders digitized their own trademark fonts to keep their past clients happy and getting the same styles they had been paying for in the past,...I assure you when a client spends anywhere from a quarter to over a half million dollars for a vehicle they don't like seeing sudden differences in their identification due to a supplier not having the same font they have bought and paid for over a couple of decades and have come to expect,...I have been told many times the reason the fire dept came back to the dealer we served was among many other factors the consistency in the way we lettered their trucks and how well it held up,.....