Hopefully by you self reporting it you will not get any fines. Your boat insurance will cover the cleanup, if necessary, but it will not cover any fines that are given. Good luck.
The conductive paste goes on the bare wire end before you put it inside the connector and then crimp it. Then I put adhesive lined shrink tube over the end of the connector to seal out moisture. No way for the conductive paste to get out of the connection.
I didn’t look at the listing but if there are no engine room photos I always wonder why not? Are they trying to hide something or just a lazy broker???
If you don’t know what model the transmission is it will be very difficult to give advice. There is usually a plate with the manufacturer, model and gear ratio on the transmission. See if there is one.