Yes indeed this was and still is a very common practice. I have dozens of ariplanes with many sizes of brass tubes as bushing.

As far as causing stray RF, yes of couse anything consisting of metal that can vibrate may induce RF but the chance of this presenting a problem is almost nil. Long ago with the old AM and even the FM radios stray RF could be a problem but it was not from wheel axles but almost always from metal clevis on metal throttle arms.

Now with modern 2.4 system this even further remote.

John