1968 Cardinals Tour of Japan Team Signed Baseball

[Rupert]

Hi All,
I'm a newbie here, and I'm seeking your knowledge. I have a baseball signed by the 1968 St. Louis Cardinals. This, by itself, isn't all that odd. However, the ball I have was signed in Tokyo when the team was on its goodwill tour of Japan in 1968. As such, there are some names here that would otherwise not appear on a '68 ball such as Stan Musial, Dick Sisler, and Bill Eckert.
I have found some info about regular '68 team balls and some info about other memorabilia from the '68 tour of Japan, but I have not found another ball signed in Japan.
My question, then, is this. What's a ball like this worth? More or less than a regular '68 ball? Is there any desire for such a piece, or is it something few people would care about? Are there collectors out there specifically interested in memorabilia from these Japan tours?
Autographs include:
Stan Musial
Lou Brock
Bob Gibson
Orlando Cepeda
Tim McCarver
Joe Hoerner
Phil Gagliano
Mike Shannon
Wayne Granger
Curt Flood
Dick Hughes
Red Schoendienst
Mike Torrez
Mel Nelson
Dick Sisler (from way back)
and Bill Eckert (MLB commisioner)
Thanks in advance for any help you guys can give!