To round out this discussion, a few shots with the Wollensak Oscillo-Raptar 75mm f1.9. There were three versions of Oscillo lenses in this focal length made by Wollensak. The first, the Oscillo-Anastigmat, seems not to be made with field curvature, and is more suitable for standard shooting. The second is the Oscillo-Raptar, made in two flavors 1:0.5 and 1:0.9 (they are quite similar in rendering). The third, the Oscillo-Amaton, also does not seem to have field curvature, but I do not have one and cannot confirm. All the Oscillo lenses I have make a giant jump in quality one stop closed, becoming much contrastier and losing glow around highlights.
Reversing this lens gives a lovely effect as well: check the last three shots here