Here are before and afters on the spring perches. I was having trouble holding a punch in place to add the tabs, and that is why I asked for ideas. I started wondering about using a shop press to bend the tabs in, but could not think of any easy way to make a die shape to put on the press ram to squish down onto the end of the bushing and make the tabs. ( I would think the right shape would press all 4 tabs in easily, without the risk of a hammer/punch/chisel slipping and dinging up the part. Easy issue for a machine shop?)
What I ended up doing was turning the end of a 3/4 inch chisel on its side, and then took a small sledge to beat the "tab" dents into place. With the chisel on its side, I was able to control it better. Probably not the best way but I got it to work for me.