I picked up this bike from a friends massive bike lot buy. See my post linked below. This bike is definitely crusty and needs some serious help but I feel it's worthy of the effort. I imagine some parts aren't original and I'm not sure what's up with the blue paint on the guard and other spots...
Somebody has a front wheel with the Schwinn Superior rim for sale on Ebay, with a good set of pictures. It looks like the Superior was single wall construction, not tubular. The seller calls it late 1940's, but I don't think I've ever seen a post-war bike with this rim.
Those Superior rims look similar to the pre-war Lobdell endrick style rims I've had on a couple of bikes. That simple, flat style with wide-set spoke holes seems to have been common in the late 1930s and early 1940s. The Lobdells had ink-type stamps inside indicating the type of tire that was intended.
The rims on Jim's bike are S-6's, with pretty clear stampings. His bike was a big part of the motive behind this thread, along with the stainless rims. For the record, his pictures are in Post #76 of this thread:
I have a brochure from the mid 40s time period (don't know exact year, assumed 1946). I guess I glanced over it because I thought these were NWs. I don't think I have seen a tandem with that guard type.