Hi Jonathan,

Thank you for contacting Mearto with your appraisal inquiry and Happy Memorial Day Weekend!
James Warren York started W. York & Sons in Michigan in 1882 and made instruments until he retired in 1917; the company changed names a couple of times, all the while using the name "York". The highest serial number for the company was 112,000, in 1938. In December 1940, York was sold to Carl Fischer Musical Instruments. During World War II the company manufactured munitions. After the war, York produced student-line instruments. In 1971, Tolchin Instrument Company who then owned York, closed the factory. Proprietary rights were ultimately purchased in 1976 by Boosey & Hawkes.
This is probably a York & Son post-war sousaphone made prior to 1971 but I can't find serial numbers to back that up.
The fact that this is so beat up will affect its value a bit.
Based on the photos and information provided, and subject to examination, this is:

A vintage brass and silverplated sousaphone
appears to be made by York & Sons (in some iteration) post WWII
Serial # 156451,
58 by 28 by 25 inches; bell 25 inches diameter
CONDITION: with denting throughout
PROVENANCE: acquired from a music teacher at a garage sale
$125-175*
*represents a fair-market value for auction purposes; retail or asking price may vary.

Please let us know if you have additional items to appraise, and thank you again for using Mearto.