Nice, I guess this is one of the more modern radial waves. I'd imagine the older ones were paired with a more ornate arm. This arm also looks like it could've held a gumball at one point too.

This Wheeler is from the late 50s. These were the first wheelers to have the integrated photocell socket. I'm not sure when the arm was made but I'm pretty sure it was sometime in the 60s since it's aluminum and like you said, not ornate. Yeah a gumball might look nice on this arm. I don't think they used gumballs here for lower wattages though. They did use teardrops on main streets from photos I've seen, though they were probably higher wattage like in the 500W range.