This model predates the E855. It’s 37mm, it’s a bumper 815 movement, with a no date dial. It was replaced by the date function bearing E855 (obviously a useful complication at that time) the E853 as a result was a more limited run, with the black dial bei...
“This example features the narrow markers, narrow alarm indicator, and ‘T’ stamped dial of the earlier manual pieces, but with the calibre 815. This combination is not common and likely from early in the production.”
If I am not mistaken, your watch dates from 1967 (serial number 1052XXX). This would be quite unusual for an E853 as indeed very few were produced after the introduction of the Memovox Auto Date aka E855 in 1959. E853 are typically in the 700XXX to 800XXX...
Interesting. So your watch would be a very late production E853. Typically 10 years later than the usual batch of 1957-1959. By chance, would you have the serial number of the movement ?
Your clasp has the date stamped at the usual place and from the photo I think I read 4 - 66 (but it's not so clear from the pic so you will read it more acurately in person)