Steinway Hamburg O Grand 1963

Louis XV from Gerald DeKerchove - The small grand with the full grand sound is Steinway's Model O grand piano. Close to six feet in length, the Steinway Model O, referred to as the “Living Room Grand,” is the largest of the smaller Steinway grand pianos with a length of nearly 5’11”. Patrick Elisha of M. Steinert & Sons’ educational division notes that the Model O’s size begins to usher in the full, rich sound of the larger Steinway grand piano experience.
 
The Model O offers a full, resonant sound of exceptional warmth and depth. Often used for homes and teaching, the Model O has a rich bass register that is bolstered by the ample string length and the patented Diaphragmatic Soundboard.
 
The Astoria, New York Steinway factory had historically produced the Model L, while Steinway’s Hamburg, Germany plant made the Model O. Over time, a consensus emerged between these two Steinway divisions that the scale design of the O was preferred. As a result, the decision was made to select just one nearly 6 foot piano to bear the Steinway name. The O had won on its merits.
 
SOURCE: A review of 6 Steinway piano models: Which is the best grand for me? - https://msteinert.com/blog/a-review-of-6-steinway-piano-models-which-is-the-best-grand-for-me