I'll agree qwith Peter ref subtracting the value of the rest of the bits. Painting may have been done for a multitude of reasons - it may have been done to cover up the word "RESCUE" which was in large friendly letters down the side.
Mine was painted when I got it, and had been done without the appropriate surface prep. Most of it has now flaked off, and I'll be applying another coat in he fullness of time. Holds air OK, but looks like a dog's breakfast.
Having said that, I pretty much bought an engine with a free hull bolted to it.......