Operators Manual For Allison Engine Installations. S/B, 10 x 15cm, 129p, 3rd edition, September 15th 1942. Published by the Allison Division of General Motors Corporation, Indiana. This little manual was issued to present engine operation and maintenance data pertinent to ground personnel, in order to accomplish reliable and satisfactory engine performance of Allison powered aircraft installations. Light soiling but good overall condition. Stock code P24215A-18.