[bigfanNY]

Well if PSA are the Experts here.. let's remember they Originally certified this ball as a 1954 Braves team ball. But lets look at what they call the ball Now
A 1954 Braves and Red Sox Spring training ball
... pretty much what I am calling it. What Sig Auctions called it.. and what it is.
Morton could have signed it any time he was in camp with the Red Sox. Same with all the other signatures on the ball. That's how it goes when collecting autographs during spring training. You get em when you can.

I fully understand that dating the ball to a specific game might increase the value.again ....might..maybe. But everything we know says this is a spring training ball. Will more research prove that all the signatures were applied to the ball on March 10 1954......no it will not even prove that Guy Mortan signed it on March 10th.
The original collector coded the balls and those codes might tell us more if you can track down some autograph collectors who purchased some of the large lots from Sig.. But I think the codes are gonna say 1954 Spring training Braves and Red Sox. But good luck with any future research.