If possible, I think you should think about keeping the watch. You will never be able to replace it.
I love wearing my father's watches as I know that every scratch and ding on the cases were put there by him.
John Cote recently posted a great photo and description of his father and a Curta calculator. It really hit home for me as I think about my father everyday and how he influenced my life. I drive an aircooled 911 everyday, just as he did. His old Seikos are not the nicest watches I have but they are among my favorites as seeing him wind and set them are a big reason why I love watches to this day. I intentionally wind my watches in front of my children hoping they are noticing - at least a little.
Good luck with your decision.
Regards,
Hiro

Hello,

: my father bought one of the first 30 Monaco 1133B in 1969 with
: steel bracelet. I got an offer for this watch and try now to
: find out the value of this watch.

: It would be very helpful, if anyone could give me a guidance.

: Many thanks in advance.