IF enough money could be found and it's a very big "IF", the John H Amos would probably have to undergo a very similar process to the Medway Queen. The Medway Queen at Gillingham Pier is not strictly the original vessel, rather (as I understand it) all of the original fixtures and fittings were stripped out of the original vessel and refitted into a new hull. This is one of the reasons why, under current rules, the "restored" Medway Queen at Gillingham Pier won't carry fare paying passengers. This is because and bear with me here, in order to get Lottery Funding, the new hull had to be built to the original plans. Therefore, the Department for Transport classify her as a new vessel, but being built to the original plans, she doesn't meet modern passenger-carrying safety standards.
This is the opposite situation to the Kingswear Castle, which used to run from Chatham Historic Dockyard. That vessel is as originally built, albeit with some modern safety aids such as liferafts added. Because she is an original heritage vessel rather than a replica of one, the Department for Transport have given her a passenger-carrying license. When I mentioned this on the old Forum, there were howls of protest from people connected with the Medway Queen Preservation Society, who would deny until the cows come home that the vessel at Gillingham Pier is a replica; they insisted that it is a restoration. The plain fact remains that it is no such thing. What you see at Gillingham Pier is, in fact, a new hull, built in Bristol a few years ago, which has had the engines and various fixtures and fittings from the original vessel built into it.
Back to the John H Amos then. That vessel was bought by her current owners with the intention of restoring her. This turned out to be rather more expensive than originally thought and the vessel has sat on that pontoon for many years, slowly deteriorating to the point where she is now beyond repair or restoration. The last time I was up close to her on that pontoon, her lower hull had collapsed where she is sat on blocks. The vessel had holes cut in the side to allow her to be lifted and was sat on the Graving Slip at Chatham for years with the tide flooding the hull twice a day. This has allowed her frames to rot and now that the whole weight of the vessel is resting on her keel, it's collapsed.
I did post some pictures on the old Forum and will have a trawl through my Imgur account to see if they're still there. If I find them, I'll post them.
As a final point, the restoration and repair of historic vessels is a hugely expensive business and always has been, which is why there are so few of them around. The most familiar examples are those vessels preserved at Chatham Historic Dockyard. HMS Cavalier arrived at Chatham in 1997 or 1998. From then, to the point where I started work at Chatham Historic Dockyard in 2008, the Trust had spent some £8 million on her. Almost all of that money has been spent on making the vessel safe for visitors to visit and on a cosmetic restoration. She will never go to sea again. Millions have also been spent on HMS Gannet. That vessel, albeit impressive, is just a shell. Going aboard, the engines, or replicas of them a la SS Great Britain have yet to be built and installed as have all the internal fixtures and fittings. The upper decks, masts and most of the rigging have been restored, so that externally at least, she appears as she did on her deployment to the Red Sea, some ten years after she was launched at Sheerness in 1878. HMS Ocelot is the vessel which has needed the least attention. That vessel was acquired by the Trust very soon after decommissioning from the Royal Navy in 1991. The Royal Navy removed all the equipment which was classified at the time, the most obvious being her flank, bow and towed array sonar systems, but also the propellers too. Because submarines are very robustly built, HMS Ocelot has needed next to nothing in the way of restoration.
