Burke passed away in 1942 but suffered a severe stroke in 1933 and was unable to sign anything after that.
Burke signatures on multi-signed items can be found, as he was a coach for over 20 years with the Tigers, Browns (as manager), Red Sox, Cubs and finally the Yankees. He played a large role in the Yankees World Series victory in 1932, imparting his knowledge of the Cubs players to the benefit of the Yankees.
Single signed items of Burke, however, are few and far between. Most especially on an official document like a contract.
The contract is also signed on the front by AL President E.S. Barnard. The Ruppert signature is secretarial.
Asking $350 delivered.