Date: 1952. Owned by Keith Loftis
The Eb Sousaphone Grand was available in 4 versions: the three valved 26K Low Pitch, three valve 27K High Pitch, four valve 28K Low Pitch and four valve 29K High Pitch. The 26K was in production from 1926 to at least 1966. The other three were probably discontinued after 1929.
The instrument pictured here has "U.S." engraved on the bell, which means it was produced for the U.S. military. By 1952, instruments in silver plate with gold wash bells were somewhat rare. All instruments from the late 1940's and 1950's I remember seeing that were made for the military have been silver plated.
What Conn said in 1926:
This model of the Sousaphone Grand was designed especially for the benefit of those accustomed to Eb basses. It is quite as effective as the BBb model both in tone and appearance. Although it weighs nearly six pounds less, the Eb is only a quarter of an inch shorter thn the BBb, and th bell diameter varies by only one inch, so this instrument adds to the appearance of the band or orchestra in which it appears quite as much as does its deeper-voiced brother.
The entire Sousaphone family was created in the Conn factories, the first one having been built especially for the brass section of Sousa's band, and consequently the present models are the result of many years of practical experience with this type of instrument. The tonal qualities of all models are pure and the scales are accurate and even.