On the subject of EA3 tires, I've been running Panaracer Col de la vies on a set of CR-18 rims for some time now and on a few different bikes. I like them a lot and never have had a flat (but they also don't see much mileage). They're well suited to unpaved surfaces at low PSI. With my dial caliper, they measure 37mm wide on those rims. For my 1940 Raleigh Sports project, I wanted blackwall tires and ordered some
Schwalbe Delta Cruisers, directly from Schwalbe USA at $17/tire. They're listed as 37 x 590, and I installed one last night on a steel Endrick rim, and at about 40 psi, they measure 35mm, which should be just right for this bike. I'm encouraged by the feel of these: the rubber isn't super hard, the look is traditional, the weight not too bad. Much better than those skinny Kenda rocks I reported on previously!