Welcome to NET54!
Awesome research & sweet early Aaron auto baseball!
On the topic of the Aaron ball, based on info above and some research on my own...
During the 1954 Spring Training & Exhib, Braves played Red Sox 8 times. x2 in March x6 in April
https://www.ebay.com/itm/38702336173...Bk9SR_Tr67L1Yw
Probably the dates I would focus most on is
March 10th Braves vs. Red Sox Sarasota,FL &
March 22nd Red Sox vs. Braves Bradenton, FL
Did Morton play in the March 22nd game? Even if wasn't he might of still been in camp based on what you mention from a March 25 newspaper he was sent down.
To me, as of now, hard to prove Aaron sign the ball on March 10th or March 22nd?
The side auto panel that has Aaron order goes...
Floyd Baker-Sox,
Jim Pendleton- Braves,
Bob Buhl- Braves
Henry Aaron-Braves
Bill Henry- Sox
With auto team style balls based on my experience, it's tough to catch and get everyone to sign in one day(hard, but not impossible for 24 players). I don't know where the original owner lived (local) or what they did, but Sarasota,FL & Bradenton, FL is only roughly 30 mins apart. Could of gotten some autographs from the March 10th game, then finished it up March 22nd.
Overall, it's a super nice very early Aaron and I would agree the ball is highly likely from March 1954.
Since this turned into an Aaron topic...it's now an Aaron photo section
Hank Aaron March 19th, 1956 New York Yankees vs. Milwaukee Braves in Bradenton, FL