77 (?) year old gold Rolex in snake skin case

[Geoff.oz]

Could the folk on this forum please take a look at the photos of my father's watch, give me an approximate idea of it's value, and perhaps provide some information abut the watch such as the model number and year of manufacture?

The watch was awarded to my dad in 1938. The engraving on the back reads:
C.F.C
Pres. by G Hendry
Best Junior
F.G. Staker
1938

The caption inside the case lid reads:
Watchmaker and Jeweller
H.S. Middleton
Broken Hill

Broken Hill is a city in the far west of NSW, Australia. Dad grew up in Broken Hill and was one of Australia's best bike riders in his day in addition to playing first grade Aussie Rules football. The watch would have been awarded for bike racing, which was very popular at the time and attracted good prize money. The snake skin case has several paint splatters which appear to be from the first house he built in the early 1940s. I do not wish to sell the watch. It is of great sentimental value, however, it is not currently insured. I would like to get an idea of it's value for insurance purposes. Any advice would be greatly appreciated.