Constellation case back engraving

Hi all, I've been getting into tuning fork watches and have been looking for a Constellation F300. I came across a listing on chrono24 that seems to be in good condition with a signed crystal and (reportedly) original crown, but the inside caseback seems to be of a different quality from other F300s I've seen. Seller's picture is below:



To me the engraved letters seem more "squiggly" and imprecise compared to other examples. I am also unsure what the "EW" logo below the reference number is for.

Does anyone have insight into whether these observations are expected for vintage Omegas? Listing is here for reference and if there are any other opinions on it: https://www.chrono24.ca/omega/constellation-electronic-f-300-hz--id20132056.htm

Thanks in advance!

Yes thank you, I think that is a better description. Would you consider the engraving in the picture to be standard/expected?