Besides, those leaky old, Wright Cyclone engines would be dripping gallons of thick black oil on the plants. The Cyclones were nasty things to do a "walk-around" inspection on if you cared about your appearance. 
The 1820 Cyclones on the Memphis Belle weren't that bad, though pulling through the prop to free up the oil was not a lot of fun. At least one engine was run up weekly for the visiting tourists so that they'd get some idea of what the beast sounded like at startup, except Number Three, which had a birds nest in it when I was a volunteer worker on the 'Belle, and the birdies were not to be disturbed. They were, in a way, grandkids of the 'Belle.
The 1820s weren't all that nasty to work on, [the Pratt & Whitney *corncob* R-4360 Wasp Major used on the Dollar Nineteen Flying Boxcar gets my vote there] but they're getting MUCH better care now, and are looking pretty good.
