Thomas,

About the Mary Lou Williams LP, I just checked my list, and I don't think that's it.

SLP 24, issued 1950, is "Mary Lou Williams and Orchestra," Gjon Mili Jam Session, Man o'Mine, Lady Be Good, Carcinoma, Star Dust.

SLP?? is Mary Lou Williams "Jazz Concert," selection from the Zodiac Suite, whether 10" or 12" I don't know.

They seem to be two clearly different records. So the later Williams may be one of your missing numbers (as may the Dyer-Bennett).

Bob