Just going to update this for anyone who happens to be looking for the same information in future and stumbles across this thread. Have heard back from Omega, the details for this watch are below.
Reference: 3513.56.00
Model: OMEGA Speedmaster Automatic Chronograph - Japon
Calibre: 1152
Dial: Black
Diameter: 39mm
Bracelet: Steel
Glass: Sapphire
Water resistance: 50m
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