Another trolling through random players resulted in landing on the Baseball Reference minor league page of Bob Will.
Will played for the Cubs...except for a short time in his final year, 1964, where he went to the Cardinals and their Jacksonville AAA team. With no transaction listed, we went to searching.
I found that Will had been named a player-coach for Salt Lake City for the 1964 season after being sent down. That didn't really help with the transaction.
Finally, I found an article from the Salt Lake Tribune of June 6, 1964.
The synopsis is a bit rough, but I ground out this translation:
" Bob Will, who led the Bees in hitting last season with a .371 mark and
has been the club's most consistent hitter this season, has been sold
by the Chicago Cubs to the St. Louis Cardinal organization. THE
CARDINALS said Ray Withrow, a right-handed hitting outfielder currently
with Jacksonville, would go to the Cubs in the transaction and be assigned
to Chicago's Fort Worth club in the Texas League. Will has been
assigned to Jacksonville, the Cardinals said Withrow was with Denver in
the Pacific Coast League last year and finished the season with the
Cardinals and was sent to Jacksonville this spring. The Cardinals said
the Will for Withrow deal was the wrap-up on the transaction that sent
Glen Hobbie to the Cards in a pitching swap that brought Lou Burdette to
Chicago. WILL HAD been a member of he Cubs since 1960, when he came up
from Fort Worth of the American Association and batted .255. His best
year in the majors was 1961....He was player-coach of the
Bees this season.
Will, however, balked temporarily when assigned to
Salt Lake and his sale supposedly was brought about by his
dissatisfaction over being assigned to Triple A."
AHA! So naming him player-coach didn't mollify him evidently, and he was dealt to the Cardinals.
This deal evidently adds to the Hobbie-For-Burdette deal as well.
That is listed on Hobbie's Baseball Reference page as:
"June 2, 1964: Traded by the Chicago Cubs to the St. Louis Cardinals for Lew Burdette."
I think we can safely edit this to:
June 2, 1964: Traded by Chicago Cubs with a player to be named later to the St. Louis Cardinals for Lew Burdette and a player to be named later; on June 5, 1964 the Chicago Cubs sent Bob Will to the St. Louis Cardinals for Corky Withrow to complete the deal.