Jon - the 38 edition was a revised and enlarged edition of Roll And Go, Songs of American Sailormen (the 24 edition). As you can see from the 38 copyright page I posted above, it has:

  A FORMER EDITION OF THIS WORK ENTITLED
  "Roll and Go, Songs of American Sailormen"
  WAS PUBLISHED IN 1924 UNDER COPYRIGHT ISSUED TO
  THE BOBBS-MERRILL COMPANY, INDIIANAPOLIS, IND.

The 38 edition was published under the shorter title Songs of American Sailormen.

I too had just been looking at Roll and Go... and noted the same things you did and was wondering if the 64 reprint was of the 24 edition. I'd planned to compare them properly later tonight.

My 38 hard copy is a US edition:

  PUBLISHED IN THE UNITED STATES OF AMERICA
  FOR THE PUBLISHERS BY THE VAIL-BALLOU PRESS


Mick