Here is a link to a liquid Graphite product called NEOLUBE 2 primarily used in model railroading, but I have used it to lubricate the turret on my Tamiya Sherman as well as the gearbox output shaft on my Tamiya King Tiger where it goes through an aluminum support bushing on the side of the hull.

It works great and is easy to apply. Basically it is Graphite suspended in Isopropyl alcohol, you just paint it on wherever or whatever you want to lubricate, once the alcohol evaporates you have a thin layer of graphite on whatever surface you chose.
While it is somewhat expensive one bottle will likely last many years, unless you are like me and find additional uses for it.
Alternately if you have access to a 3D printer you could print a slipsheet out of PLA or ABS to go between the turret and the hull the PLA and as you mentioned ABS are both very slippery.
Steve