I have 4 of these Nixon Galloway aircraft art 8 X 10 water color paintings, not prints, with Galloways sig at the bottom left of each. The 1926 Curtiss Carrier Pigeon, the 1926 Ryan M-1, the 1931 Fokker F-10-A, and the 1926 Ford Tri-motor. I received these from a gentleman having a garage sale of sorts, he let me have them for free. They in excellent condition. Anyone have a clue what their worth is?