Mark and Alan, the bar is a padded restraint used similar to what you find in an amusement ride. I didn't see any seat belts so my guess is that is a substitute. When in the down position, it covers the entire width of the passenger compartment. I'd never seen anything like it before and wondered if it was legal given that this was an antique?
I don't know about legal or not on the restraint, but I can tell you based on my experience riding in a 1928 Model A a friend of mine has, any restraint would be welcome, especially since there's no doors on that one. 50 mph sitting behind a plate glass window without a seat belt is downright scary for someone who's grown up wearing seat belts all his life and doesn't really feel 'connected' to any car that doesn't have them when riding in them.