Here's an article that I found in a "TV Magazine" from the St. Louis Post-Dispatch newspaper. It's dated December 22, 1957, so it's a very early story about JK in Maverick. He had debuted as Bart only about a month before. The Encore Westerns Channel is re-running the first "Bart" episodes now, and I thought it was interesting to see how the public reacted to the new Maverick on the block back in '57. The good-natured kidding between JK and James Garner is also interesting:
"Mavericks Steal Thunder
From Sullivan and Allen
by Vernon Scott (UP)
Ed Sullivan and Steve Allen have called off their rating feud to battle a common enemy, a pair of Mavericks named Bret and Bart.
A big surprise of the 1957-'58 TV season is the way Maverick has stolen the thunder and audience from the two big variety wheels.
On the air only 13 weeks, the hour-long horse opera passed Allen in the Trendex rating the second week out of the barn. It took six weeks to catch Sullivan.
The success of the new entry is credited to its rough-and-tumble stars, James Garner (Bret) and Jack Kelly (Bart).
...Both are delighted that their show is whipping the opposition, but they refuse to needle either Allen or Sullivan.
During lunch the big guys spent their time ribbing one another about Kelly joining the show six weeks after it went on the air.
'Turning out an hour show on film was too much for one actor,' Garner explained. 'I was working 14 hours a a day, and we were falling behind schedule. So we decided to write a brother into the script.'
'That's his story,' Kelly put in brashly. 'The ratings were lousy and they needed some real talent to pull it out of the hole.'
'He's crazy,' Garner fired back. 'We needed comedy relief, and believe me, Jack's funny in this role, even though the script doesn't call for laughs.'
Warner Brothers studio, which films the ABC-TV show, says Kelly is 30, Garner 29. Both stand over 6-feet tall. Garner might get the best of it in a free-for-all. He outweighs his TV brother by 20 pounds.
If Warners decides to write more brothers into the script, they might consider Sullivan and Allen. They still have fairly large followings."