I just bought a boat with 6s on it

i see there is a leak on the seal on the propellor shaft.

I need to order some parts but I see on the schematic they are different between the two.

how can I confirm which one is installed on my boat?

The dry sumps have swept back skegs as I recall

That`s something you should definitely know, for parts and especially oil changes..
Easy way to tell is the tie bar mount on a dry is on top.
These are wet, tie bar mount is in front.
Jtee is right also.