Tamiya has, with the release of the #56020 Leopard 2A6, introduced a Turret Bearing Race you can get as a standalone spare part ( you'll need 3 separate Bags: The 5-Piece Bearing Race, a Bag of Bearing Balls and a set of Tamiya self-tapping Screws ) that is super nice for any build that fits it and was so far also used in the JGSDF Type 10 and M1A2 Abrams - The concept has since also been adopted into the M551 Sheridan and Centurion Mk. III but there it is part of the Hull and or Turret itself and as such cannot be used elsewhere.
I've used it when I turned my Display Model #36208 Gepard into a Full Option Model and with my D.I.Y. E-100: E-100 Fidget Spinner - IMHO, highly recommended!