I think a 12.8m serial is more likely to be 1950 or even 1951 than 1949. I think it looks fine, though the second pic gives the faint suspicion that the hands may have had a relume at some point. Having checked one of mine, a 2577-6 there are some differences admittedly but I would still suggest it looks OK though since there were many many 2577 versions, some even without the Seamaster script at all and that does look like very old patina with pink radium lume still evident.
My 12.19m serial 2557-6 which after a bit of research I dated at 1950:
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And an earlier 1949 11.7m serial 2577-4 without the script:
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