[RonC]

I've pulled apart many wheels-tires that had no rim liners at all and the tubes were decades old and still held air. Personally I use liners as I feel it adds a little extra protection against scuffing on the tubes. Your rims could be pefect now but get some water in there and rust will start to form creating an abrasive surface. In addition tubes available today do not seem to be anywhere near the quality rubber of older tubes.