I don't know about your 43, but the 356 has a major design fault with the swim ladder: If you have the "seat"/walk through down it covers the ladder, you have to step through, close the seat and deploy the ladder. Not good design IMHO, especially if you had left the seat down and fell overboard.
It should be designed to pull out aft, then be able to fold down, with seat up or down.....on my todo list. If you were to have one fabricated I would consider a different design, not that difficult.
Neil