Might check on how many gringos disappear in the ride between coasts. Never met a truck we would trust. Can't you raft up with a bigger yacht and go through? Or maybe do the trip of a lifetime and go via the Horn.
i lived here 15 years i can put you in touch with an engineer here from texas moves heavy equipment but my guess is it will cost you 3 or 4 times as much cross country then you have the lift and launch both side
or go up the Escondido river in cheaper Nicaragua to the international port of El Rama, drive it across a flat and new road and drop it again in Puerto Corinto, where for sure they have dry dock and cranes to put you back in. Bluefields (El Bluff) would be the port of entry