I've looked a Sleepy Eyed John some and figure it might be written by
Tex Atchison.

"Atchison also kept his hand in at Western swing, joining fellow fiddler Rocky Stone, and many other fine musicians in Ole Rasmussen and the Nebraska Cornhuskers. The leader of the group doesn't sound like a Texan, but it didn't matter. He was simply a businessman who kept the band together, proving with his hiring of Atchison that he knew talent when he heard it. The group recorded more than two dozen sides during a two year stint at Capitol which began in 1950. Classics such as "Sleepy-Eyed John" and a version of the jazz toast "C Jam Blues" reveal Atchison's graceful way with the Western swing style." Eugene Chadbourne, All Music Guide

Johnny Horton's version (Sleepy Eyed John 1960) probably came from Atchison who played with Horton shortly after his stint with Capitol.

In Keith Lawrence's article (see complete article after lyrics) "Tex Atchison Chose Music over the Mines:" Atchison was born near Rosine on Feb. 5, 1912. Five months earlier, William Smith "Bill" Monroe had been born on the farm next door. The boys went to school together. But the musical paths they followed took them in different directions. Monroe became known as "the father of bluegrass music." Atchison found his fame in western swing.

It's quite likely that both Atchison and Monroe learned the same tune probably from the same source. IMHO Sleepy Eyed John seems to be a re-write of Casey Jones (Copyright 1909 Words, T. Lawrence Seibert. Music, Eddie Newton)

CASEY JONES
(Words, T. Lawrence Seibert. Music, Eddie Newton. Copyright 1909.)

Come, all you rounders, if you want to hear
A story about a brave engineer.
Casey Jones was the rounder's name.
On a six-eight wheeler, boys, he won his fame.
The caller called Casey at a half past four,
Kissed his wife at the station door,
Mounted to the cabin with his orders in his hand,
And he took his farewell trip to that Promised Land.

CHORUS: Casey Jones! mounted to the cabin.
Casey Jones! with his orders in his hand.
Casey Jones! mounted to the cabin
And he took his farewell trip to that Promised Land.

The similarity is too great for coincidence. Compare Sleepy Eyed John:
SLEEPY EYED JOHN (Chorus)

Sleepy eyed john, better get your britches on
Sleepy eyed john, better tie your shoes
Sleepy eyed john, better get your britches on
Try to get to heaven 'fore the devil gets you.

What do you think?

Richie