You are absolutly correct about your observations. We have replaced the iron tank with an Aluminum
tank, I recently took the deck
down to bare wood... and yes found a couple of punky spots, however, they were not too big and I was able to repair without to much trouble. As you said about the 35, We really love Tivoli and the overall performance she gives us. But do be careful and check the decks and cabin top closely for soft spots, especially where the deck
meets the sides, probe it close.