When I found an old German generator engine (story in Gas Engine Magazine, May 2006), it was so nasty looking that I just had to paint it in its original color scheme. But when I bought my very first antique engine, a 1927 Economy 1-3/4 HP S, in Portland, Ind., in May 2005, my manhood was threatened by two of my engine collector friends if I ever painted it! They both indicated that if this engine would have been painted, they would have recommended I not buy it! Paint can hide too many things. And as I read on SmokStak one time, "It can only be original once." With this being said, I will not paint it.
When engines like the ones in two articles in the April GEM, the Jaeger restoration, page 9, and Peter Rooke's Amanco, page 11, they were so rusty and nasty, that they had to be painted.
Last year in the Monroe, Mich., engine/tractor show, there was a hit-and-miss antique engine (don't recall the manufacture or year) that I thought was only a lawn ornament. When my brother-in-law and I reasoned that was all it was good for, the owner said it ran; he rolled over the flywheel by hand and away it went! It was amazing! If this engine would have been painted, I believe that it would have detracted from it.
That's my thought on the subject,
Karl T Schwab