I know this will sound strange. There seem to be differences in how the fonts render on my modern computer, compared to the old-school physical stamp font.
I was trying to track these down a couple years ago. This photo shows a sample of what they called 'Roman' although this particular stamp (TX, you may recognize?) is much larger than the wiper stamp. The other style was called 'Gothic', I think it was mostly used on newer cars?
At the time I was researching this, i ran into a problem. This type of stamp was being discontinued and I was unable to place an order (this was summer 2022). Had an order in progress but it was cancelled/unavailable.
I tried to revisit some of the shopping links I saved in 2022. Not yet found one that works (dead links or moved)...