Saving Old Seagulls

Hello All,
I wonder if anyone could help, I've been given this gear box and prop but I am not familiar with it and wonder which model seagull it came from and what gear ratio it would have, it's direct drive, a round casing I've never seen before and a 4 bladed prop with 100P on it, which I'm not is correct with this gear box, Any help would be great, Thanks.

Rene

Same as on my Century 100 1960 ish
3.5:1 I think without checking.
Mine has a five blade prop.

Actually no its a bit different in that it has 3 screws holding the cover on??

It's from a Century 100, 4:1 ratio, fixed drive, fitted to CP, WP & SP 1966 to 1973.

Thank you Guys,
Have a nice day

It happens that I just finished revitalizing a CP Sea Gull. Same "turnip" Gear box. See pictures. Art

Yep, I have a '63 CPL just like it - I won't look as good as that when it's finished, unfortunately