Well, these might fall into the "close but no cigar" category.

There's Andy M. Stewart and Andy Stewart. At the time I first heard of him, Andy M. was touring the US with Manus Lunny, but I don't think he was using the "M." I was confused when later I bought a tape cassette at a Scottish festival of "Andy Stewart." I was bitterly disappointed when I got it home and realized it wasn't the same guy. Later I developed some appreciation of the earlier Andy, so all was not lost.

There is (was) Jimmie Rodgers the singing brakeman, Jimmie Rodgers of "Kisses Sweeter than Wine," and Jimmy Rogers the bluesman.

There's Sheb Wooley and Shep Woolley, also on opposite sides of the pond.