1957 Giants Proposed Uniform?

 By JT 

In October of 1957 Willie Mays at Seal Stadium in San Francisco wearing a Giants cap and uniform that was quite different than the one worn in New York and the one they wore subsequently in the Bay Area.

The "SF" was different and there was trim around the front buttons. I know nothing about this other than the photos exist. 

Here are a couple more—

Can only guess that it may have been a proposed idea that was nixed. Anyone else know?