These are commonly known as split rims due to the split ring front rim flange. The main benefit of this type wheel is ease of installation of the early 8-10 ply heavy duty tires that frequently used an inner flap between the wheel and inner tube. Back in the day when tires were installed with tire irons, removing the front ring was much easier than attempting to stretch the tire over the rim. On very heavy flaps/tubes/tires removing the ring was essentially the only way to mount the tire.
The danger occurs if the split ring is damaged or doesn't seat correctly. Upon installation, or later during use it can separate from the wheel with explosive force. 60 minutes (CBS) did an feature on the numerous fatalies caused by these rims back in the 70's when they were more popular on big rigs, and may be partially responsible for why they are so rare now. When a ring blew off a fully loaded big rig it frequently took out the car and occupants next to it. That's why it's hard to find anyone willing to work with them today.
If I were doing a 100 point restoration with original style heavy duty bias tires I'd want to keep them anyway just to keep it pure. If it's going to be a driver, modern tires and wheels will be more comfortable and handle better. Regards, Mark.
