I think we can solve the mystery with some research. The Warriors moved to SF for the 1962-63 season, and we know it isn't a 1959-1960 or 1960-61 image because the jersey is wrong. So it has to be a 1961-62 team issue. Here's a photo from the 100 point game:
The jersey looks to match the style.
And, just because I ran across it:
is that astonishing or what?