One of the stories I wrote for Spontoon Island, "Felis Ex Machina," has a scene involving a minstrel troupe (the story is set in 1937). To give an artist some background/reference as to what one looked like, I gave them this:

This is a 1927 editorial cartoon from Sydney Strube, the longtime editorial cartoonist for the London Daily Express.

The figures represent the then-current Cabinet of the Conservative Government. The figures are, from left to right: (1) Lord Birkenhead, head of the India Office; (2) Sir Austen Chamberlin, Foreign Secretary; (3) Sir L. Worthington Evans, Secretary of War; (4) Prime Minister Stanley Baldwin; (5) Sir William Joynson-Hicks, Home Secretary; (6) W. Bridgeman of the Admiralty, and, yes, (7) Winston Churchill, over a decade before he became PM, at this time Chancellor of the Exchequer.

(The figure in the foreground is Strube's "Little Man" character, his equivalent of John Q. Public.)

Some of the elements of the traditional minstrel show, which continued to be popular in England in the 20s and 30s, are seen here. Baldwin is the Interlocutor, with Birkenhead and Churchill as Bones and Tambo. The traditional horseshoe arrangement is also seen here, as are the outsized bow ties.

This image was taken from the first Strube annual, published in 1927. They're not all that common; I have some of the run from the 20s, 30s and 40s.