Yesterday, I found a news archive site that includes page scans from the 1967 St. Petersburg Press. The February 26th issue had the spring training rosters of the teams training within 110 miles of St. Petersburg (Phillies, Cardinals, Mets, White Sox, Red Sox, Pirates, Reds, and Athletics).
This is a 42-man roster. (John Briggs and Mike Wegener are designated as on the "Military List", so maybe they're not counted toward the 40-man roster.) The non-roster invitees are listed at the bottom, and include veterans Ruben Gomez, Joey Jay, Jim Schaffer, and Jim Gentile.
Besides players that appeared for the Phillies in 1967, this roster includes future Phillies Billy Champion, Larry Colton, Lowell Palmer, Bill Wilson, Larry Bowa, Denny Doyle, and Larry Hisle.