Does someone know at what serial number range that Illinois started using the straight line Block font on the Illinois Getty Model dials?

I can't pin that down to a serial number for you Bila.

Later when Illinois went to the curved "ARC" type signature, and after the production of Getty movements had ceased, the curved arc started about the 3,000,000 serial number.

My best "guesstimate" might be somewhere around 2,300,000-2,500,000

Not much help......

regards,
bb

Thanks Buster, with that info and a catalog picture I have that kinda fits.