Inheritance help and advice

[SBdG]

Hi All,

Some time ago I inherited a vintage Rolex. I would like to learn more about the watch, see if it is authentic and find an original buckle.

I think the watch is a 1946 Rolex Precision. It has two numbers stamped on the back: 519038 and directly under this 773. The watch has a stainless steel case, a gold bezel and a rose gold crown. The face has a sub-second hand and has been refurbished. I don't know if any of this is how it came out of the factory. Attached are a couple of pictures.

Any information would be welcome. In particular, what the original buckle looked like and where I could buy one.

Thanks!