I started with Steinway in the early 1980's as a fill-in tuner for their Harlem church customers, and, as a subcontractor, did troubleshooting on problem uprights.  I became something of an expert on pre-WW2 uprights, which were [and still are] notorious for their balky double flange actions and double tenor dampers.  I have worked on over 3000 of these pianos, doing repairs ranging from fixing sticky keys to total overhauls.  Nowadays, in an unofficial capacity, Steinway also often sends me the uprights from the Korean War era. and later., the 45" studio and the 40" console, which present different problems.