I'm always reluctant to be too critical of ship preservation projects, because I'm at least generally familiar with what these people are up against.
Taking on such a project means committing millions of dollars to the ship's acquisition and initial repair and restoration. And even if that initial expense can be met, and the ship is opened to the public in reasonably good condition, the money has to keep pouring in, year after year, as long as the ship exists. A lot of projects go downhill because the responsible organization managed to raise the initial funds, but couldn't find money for improvents, repairs, and ordinary maintenance.
A few years ago one of our grad students wrote a thesis about the preservation of several preserved American WWII warships. One of the major things he found out was that the steel used for most hull plating and structure has a limited life; when it gets to be more than 50 years old or so it starts losing its strength. These ships are now at least 75 years old. That's probably why several embarrassing problems with leaks have been taking place.
The example nearest to me, the U.S.S. North Carolina, has been leaking like a sieve for several years. She needs lots of new bottom plates. The proper way to do such a repair is, of course, to put the ship in a drydock - for several months. The nearest facility that could do the job is Newport News Shipbuilding and Dry Dock, which is several hundred miles away. For a while there was talk of towing the old girl up there, but that would have cost close to a hundred million bucks. The state just doesn't have that kind of money, and the ship's private support group doesn't either. (And while she was drydocked the revenue from admission tickets would disappear.) The organization is now talking about building a series of cofferdams at crucial points around the hull and pumping the water out of them, so the welders can work on the weak plates. I don't know how many years that will take.
The correct long-term solution to hull decay is to take the ship out of the water and put her in a permanent drydock. That costs huge amounts too - and the public seems to have a fascination with being able to see the old ships afloat.
The North Carolina's decks make a happier story. Her main and boat decks originally were teak. They got banged up in various ways during the war, and the bad spots were patched with some sort of mastic. A few years ago the governmant of Mayanmar donated several thousand square feet of teak, and gave the ship a bargain price on what was necessary to complete the job. (That may have been the last civilized act the government of Mayanmar committed.) So now she has beautiful, smooth teak decks. (Small catch: At about the same time, the authorities decided to paint her in the dazzle camouflage she wore in the latter part of the war. I'm sure they're aware that the decks were stained blue at that time, but they elected not to paint that beautiful teak.)
Incidentally, they chopped up lots of the original teak into convenient sized pieces. You can buy them through the ship's gift shop.
It needs to be remembered that, regardless of how many glaring mistakes we see in a restored ship, there probably are financial reasons behind them. I'd never dream of working for such a project.
I suggest we continue being critical, but also be sympathetic.