Correct crown for Yacht Club ref 811

Hi.
I am in need of an original crown for my yacht club. Can't seem to find answer to my questions neither here or on the www so I'm reaching out to you guys...
First of all - I believe these should be fish Crown, right?
Secondly - what are the correct dimensions as to width, height, tube size etc? And lastly what should it look like profile wise, I see some with a flat end and some have like a ridge going all around the periphery of the end of the crown.
Best regards, Ryan

Found an older image on my server.

Maybe it helps.

Can someone tell me if on the Yacht Club the numbers were ever not 15 30 45 and 60 but 12 2 4 6 8 10 in the lower dial.

It sure does. Thank you so much :-)
Maybe also someone could chime in about the correct dimension of the Crown?

Here's mine...

Thank you for your time and effort. Much appreciated