Brian played with Paul Rodgers years before Paul started his association with Queen. But the BSO did record a version of Crazy Little Thing Called Love - it's on the Japanese Vavoom! and also on the "Jump Jive and Wail" best of the BSO that was released in North America. It's quite good. Stray Cats also threw an informal version together for some shows in the early 90s.
It would be interesting to know if the two Brians have ever met. Surely, there would have been some industry function over the years with both in attendance, but I've never seen or heard of such a meeting.
Brian May or May Not-a-billy