1931 Cushion, Gold

[Icuricub]

1931 Rolex, gold, cushion.
I've not been able to find similar online that have the exact same features: a plain bezel, Rolex Crown on the dial, and no 'Oyster' on the dial. This watch is part of an estate passed down to 3rd generation from original owner. It's also dated (year: 1931) on the back (by original owner).
Any info that will help us better understand the watch, value, scarcity, uniqueness or otherwise etc would be helpful.
I'm not an horologist, though pls ask any questions and I'll try and answer as best I can. Thank you.