I bought a pair of those - pretty much just like yours - new in the late 60's if I remember correctly. I have three new "Brushfire" brushes - red/orange rubber handles with similar wire handles but with a wire loop end instead of the ball. I like the feel of the rubber handled brushes = nice grip - and the metal ends give a nice effect on cowbell/block/cymbal bell etc.

Nice brushes you have there.

I believe these were quite common in the 60s. They are cool and very versatile. Mine are from the early 60s

I also had many of these but i never thought they were meant to be mallets as every time i hit with them they bent i understood but I may be wrong that the ball was just to keep the wire from going to far into the aluminum sleeve and the ball was just for comfort for your hands...

YES! How many of us used those rubber balls on the ends as mallets? They were perfect for cymbal crashes when you were in "brush mode" with the wire rod fully retracted into the handle. However, if the brushes were retracted and the metal rod with ball was extended, using them as mallets always bent the rod. Probably why it's hard to find a vintage pair in perfect condition.