left and right front T-Bars?
 

I just got my 23mm bars for the front and they are not marked L or R, its been so long since I changed any of these I cant remember if they are interchangeable or not. The rears are marked, as well as the original fronts, but not the new ones. Correct or not?

My new SwayAway rears are marked and the used fronts I bought are marked as well. They are white, I'm thinking they are SaW too.

I think Sanders are not marked?

With the new ones it doesn't matter. The markings are there for referene in the case of future removel & reinstallation (you must reinstall the same way)

they take a "set" from all the twisiting -- i.e. grains in the metal are either aligned or distorted in a spiral fashion. New ones are not like that so no prob.

You could hammer an L and an R into them or use a marker crayon or maybe a Sharpie would last. Or just keep them marked after pulling out the next time you pull them.