I've always used 1/8 music wire for the post and the hole in the bushing is larger causing some slop. The other day I was looking for some 1/8 wire and came across a piece of wire from a political sign support. It's a perfect fit. I know it's not as stiff as the music wire but trying to bend a 2 1/2 inch piece by hand isn't possible.
That's inexpensive wire and it's not tempered. I wouldn't use it.
Unless the sign industry has changed?
Why not sleeve the post and drill out the bell crank? This will remove slop but not ware.
Once the lines are tight, the slop isn't felt, or is it?
Why are you bending a 2.5" piece of wire? Heat will do this and a good vice. I bend 90's all the time with mu wire bender?
Do you have a wire bender?