I don't think anything is learned by straight scans with no post processing. The scanned image shouldn't be about what it is, but what it could be. It is what darkroom work, and now scanning work, is all about, post processing to achieve the goal. All sorts of things come into play to confuse the issue with a straight scan, such as the inherent contrast of some lenses rather than the inherent sharpness of others. And often contrast is confused with sharpness, like the Zeiss have an inherent contrasty 'pop', while Leica and Olympus lenses are less show off and concentrate on sharpness and rendering. I can't see anything in the original steam engine picture that couldn't be rectified by some post processing of the image.