By no means exclusively. I've seen him onstage with a Gibson many times. He uses only 5 strings on his Fenders, which are in Open G tuning, and he uses the Gibson as his 6 string guitar in standard and other open tunings.
Keef is famous for Tele's & LP's. Gibson is famous for "poor marketing".
And other than Chuck Berry IDK anyone that plays a 355 except for guitar nerd JB.
And the only reason KR played a 355 is b/c Chuck did and Richards copied about everything Chucky B. did he has said himself.
Once back in the dressing room before a show Keef picked up CB's Gibson and Chuck kicked his ass.
Well known & documented.