Thank you for your assistance I have looked through the catalogues and I have found a stopwatch like mine its Ref 902 or maybe 503 the serial number inside is 537389 but the number on the case is 539083 and mine is brass not plated, if you can tell me a bit more I would appreciate it.
Thanks for your message and your picture. Your stopwatch looks more to be a ref. 902. To be sure it’s not a 530, the movement should be inspected since the 530 and the 902 have different movements. Small logo like on your stopwatch dial is mostly found on 40’s early 50’s stopwatches.