Based on the serial number shown in the photos the horn was made in the early 1910's (1913 or so). It appears to be silver plated and the case looks very nice (which is unusual for these horns). A label on the case says USQMC, indicating that it was made for the military. Starting bid is $1,225 and shipping is $55 (est.).
SOLD FOR $1,225!
https://www.ebay.com/itm/255044010634