I've been attending bluegrass festivals, both large and small, for more than 35 years and, like Barbara, don't ever remember seeing the S&B displayed, either privately or for sale. Actually, there was one exception. In Berryville, VA, (actually Watermellon Park on the Shenendoah River) in the mid 1970s sometime, a bunch of drugged-out bikers from nearby Winchester showed up. They weren't musicians or even bluegrass fans—they kept insulting and threatening everyone—they waved guns and screamed about how much they hated bluegrass until the drugs wore off and they began falling, rather like H.G. Wells' Martians. People would walk by their comotose forms and kick dust on them. These animals are the only people I remember displaying the S&B at a bluegrass festival. For many people on both sides of the Mason Dixon Line, that has become what the S&B represents today.

pdq, Bill Monroe was born in 1911. He considered himself primarily a blues singer and claimed the African-American musician Arnold Shultz as one of his major influences. A young Bill Monroe used to play as Shultz's sideman from time to time.¹ And you're right, though I don't think Bob Black is among them, Bill had quite a few Jewish musicians in his band. Bill valued musicianship above most other things—though he was known to be intolerant of homosexuality, at least in the 1950s, and excessive drinking.

      - Mark

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^1. Actually, it was common for African-American string bands to play the same tunes in pretty much the same way as the white string bands. The white bands actually learned from the African-Americans. The reason we've forgotten this is because of the way the record companies pigeon-holed the musicians they recorded. For an excellent discussion of this, see Elijah Wald's wonderful new book Escaping the Delta: Robert Johnson and the Invention of the Blues.