Oyster Royal Precision identification help pls

[Greg Tebb]

Hello guys....newbie here looking for help identifying the year of manufacture and details of my Rolex Oyster Royal Precision.
The movement has the serial number 80785
The case back has 6427, 1.61 and 6426 in feint.....
There is also a finely ‘scribed’ R45755 with a date and initials (hard to read)
The lugs have 594947 and 6426

Can’t figure out how to easily attach pics?
The outer bezel is smooth polished not the engine turned variant.

Could you guys help with ID and a value for insurance please

Regards Greg