Contains primarily correspondence between Ratz (in his role as President of the International Gustav Mahler Gesellschaft) and Cooke but also includes other items, details as follows:

Cooke to Ratz: [14 Feb 1961] German, carbon typescript, 7 pp.
Ratz to Cooke: 2 Mar 1961, 2 pp.
Cooke to Ratz: n.d. [c.Mar-Apr 1961], German, carbon typescript, 3 pp.
Ratz to Cooke: 11 Apr 1961
Ratz to Cooke: 24 Apr 1961
Cooke to Ratz: [27 June 61] German, carbon typescript with Goldschmidt’s handwriting and initials on it
Ratz’s secretary (Emmy Hauswirth) to Cooke: 30 Jun 1961
Ratz to Cooke: 22 Jul 1961
Ratz to Cooke: 25 Apr 1962
Cooke to Ratz: [18 May 1962] English orig. version [revised in blue fountain pen], 3 sides on 2 pp.
Goldschmidt’s translation, 3 pp.

Also includes:
Ratz to Peter J. French: 19 Dec 1966: photocopy of Ratz’s letter, in German, 2 pp. with English translation
IGMG Committee Report, 1963; photocopy, 8 pp.
Leaflet (German) announcing the Ricke facsimile of the draft and materials of Mahler’s Tenth
Symphony; 1966
IGMG (Dutch section): First Newsletter 1967; apparently sent to Hans Keller (‘Chief Asst’) and forwarded to Cooke with a handwritten note from Keller’s in Dutch

Note: most of the letters are in German with some accompanied by English translations by Bernard Goldschmidt.