1890s-era Conn BB-flat Tuba?

[Chuck4]

Hi, folks; woodwind player here, attempting to ID an older tuba. BB-flat raw brass, stamped: "MODEL" (impossible to see what the model actually is; maybe a single letter like L or D?), "MADE IN ELKHART, IND[IANA], USA." Serial # 19963. Made in Elkhart, we assumed Conn. Serial number of 19963, we assumed a mfg. date ca. 1890 (two sources have compiled Conn serial numbers going way back). Might accidentally be a Conn Pan-American (but that was a student model horn, and we think this was originally used by a professional). Really trying to ascertain its chain of ownership (recently came from Willow Grove, PA, but we think original owner was in Washington DC), and Conn does not have a historical dept. Anyone know of a source that shows Conn's sales records back that far? And can this model w/ serial number be definitely considered Conn? Model name? Thanks for any info!

[windshieldbug]

There were lots of companies in Elkhart besides Conn.
You may want to try Horn-u-copia.
https://www.horn-u-copia.net/

[Chuck4]

Excellent info! I already see at least two companies there that might be additional contenders; thanks!