The bronze bushes can work very well if you lubricate the machine regularly. They are often designed so that the grease that enters through the grease nipples can only get out by passing through the small clearance between the bush and shaft, forcing out the old dirty grease as they do so. Just check as you go, though. Traditionally such machines has no grease seals, which was fine as long as you greased them regularly, but awful otherwise. Later ones had grease seals installed backwards, so that grease pressure lifted the lip and allowed the dirty grease to pass through. However, I once had a Japanese scooter that had the seals in the "right" way around. First time I greased the front hub, both seals popped out. Irritating.
