Bezel's font on vintage Speedmaster

Dear All
I have a question to propose to the forum.
While searching for my vintage Speedmaster, I had the opportunity to observe several examples.
I noticed that the font of the bezel changes, in some cases quite a bit. Even the accent on E comes and goes.
Does it depend on the different manufacturers or could it be that in some cases they are fake?

Here are some examples. Note that they are all vintage models between 1966 and 1969 except B (I don't remember if 76 or 78).

I'm sure you know more than I do.

Thanks for your attention

A 145022 '69 / '70 smooth case - DNN

B 145022 mid '70 medallion case - delivered from Mexico

C 105012-66

D 145022-69 smooth case - DO90

Sorry if the photos got mixed up.

Yes, there are differences and some attributed to what Dan S stated. If you are truly interested get the reference book, Moonwatch Only by Rossier and Marquie.

I took a few photos of pages from their book, if this is inappropriate, please remove images from reply.

Wow! Thank you Marsimaxam, this is the definitive answer!
I have to decide to buy MWO, once and for all.
And Yes Dan, you are right, a watch must be looked and appreciated in its entirety. Mine was just an enthusiast's speculation.

I suspect there were more changes and variations then documented. Bezel printing 40+ years ago wasn’t as accurate as it is now. Back then there were limitations with precision during production. There would’ve been differences in the margins, alignment quality and other irregularities.