Unknown Vintage Rolex

[BennyH26]

Hello all! I was recently given the pictured vintage Rolex from my father. It was given to him as a gift circa 1950s. I've searched on Google and eBay for hours, but can't find this exact model. It appears to be gold plated with "20 Microns" written on the inside band along with "RolexSA"

On the face of the watch, "Rolex Oyster" and "Precision" are visible. Does anyone know what the model of this watch is and it's approximate value?

Thanks in advance for your help!