It cries out to be modernized; maybe ducted fans, contra-props or composite propellers.
Of course, converting one as an LCAC(H), the Landing Craft Air Cushion(Heavy) is a natural. I'd just hate to see what type of ship can take one of these in the well deck! Perhaps if you carried them as deck cargo on one of those semi-submersible ships that float-on/float-off cargo.