The only antique transistor radio I have is a 1958 Zenith Trans-Oceanic Royal 1000. The rest of my sets are from the '70s, with one (my Zenith R-70) from 1980. Still excellent performers, although the dial cord on the T/O 1000 broke so I have to turn the tuning cap manually to change stations. That isn't an issue for me, as I keep that radio set on AM 740 in Toronto.
I recently put a new set of batteries in it and I use it occasionally, but not much, so the batteries should last months or years -- I've heard that the solid-state T/O's don't draw much current, so a set of batteries should last me a good long time.