here is one like above, with additional Turler script, original blue second hands and non-luminous hands. Cal .352.
Thats an interesting stap, do you have a picture that shows it a little better? Would love to see it.
Funny thing is generally speaking a 2520 chronometer is a fairly uncommon Seamaster, it just happens that there's actually quite a lot of them around here.
I believe mine is actually a 2577 Not only is the OP dial redone, and pretty poorly at that, the case looks severely polished... I believe the crown is not original either.