I stand to be corrected (my limited experience is based on '32-'34 wheels and brakes), but aren't there actually three areas of contact? The raised ring on the hub/drum inside the stud circle (the five marks on your wheel), the pressed ring in the wheel hub just to the outside of the stud circle (circular ring on your wheel) and the outside lip of the wheel against the step in the drum?
I am genuinely interested in this as I have a '30 Coupe that I should be mechanically restoring over the winter, and it came with a mixture of '40 steels (that definitely don't seat correctly) and '35 wires, that appeared OK before I removed them. I am planning on using a set of 17" '34 wires, assuming they fit correctly.