Any information about this vintage Rolex?

[RobinB]

Hello everyone,

I signed up for this website to find out more about my watch. I got it from my grandfather a time ago. The glass of the watch (plexi) is damaged. It's a 'Rolex Oyster Speedking Precision', at least that is what the front says. On the bottom side of the watch, the serial number '71909' is engraved. On the other side, at the top of the watch, there is engraved: BREVET +. It is a manual watch. After a quick look on the internet i found out that the watch is from 1935. (According to the serial number). Can you guys tell me a little bit more about this watch? Is it really that old?

Thank you all in advance,

Robin

P.S. Images from the watch in the attachements