That's really cool.
HUGE SIDEBAR:
When I wasn't old enough to drive and maybe I was in the 9th or 10th grade, the Memphis Park Commission Band was still going. They would rehearse in a community center that was designed for people who had mobility issues. They had a special swimming pool for people who didn't have use of their legs, etc.
At that time, the band was still directed by R. Roy Coats, who was the retired band director from Humes High School (as well as having been the first band director ever at Ole Miss), and had been the band director at Humes when Elvis attended. He was also a composer and had written some band pieces that we played in that band. At that time, everyone called It "Coats' Band" rather than by its formal name, the Memphis Park Commission Band.
In the storage closet was a beautiful new looking 36K fiberglass sousaphone and a beautiful new looking full-sized version of the one that you're offering for sale. The full size one of course had a three-quarter inch bore. I would play it at the rehearsals and was sort of proud to be playing it. One week, an older guy - who smoked cigars - took it away from me and took it home. After a few weeks he brought it back and quit the band. The thing smelled like cigar stench, and he had dented and scratched it.
What weird memories some things trigger.
Notice that he didn't allow Elvis to enter the high school talent show at Humes because he judged Elvis has not having any talent. Don't think too harshly of Mr Coats. There are numerous quotes of numerous people who grew up with Elvis claiming that his voice was not very good ("weak", etc.) at all when he was in school.
https://ourmemphishistory.com/band-dire ... roy-coats/