It is engraved with the upper-case initials USN... Possibly a horn used in the United States Navy.
This instrument is made of silver plate with a satin finish and has a gold washed inner bell. This is a historical horn; it has been left original for the collector or admirer of Buescher quality. There are various small dings and scratching and there is faint slide rash on the bell, but still quite clean.Even though the inner plating on the slides is very worn, the instrument still plays well and t. He slide action is good, with decent compression.
This horn has a unique and innovative threaded slide-lock for its time; very effective. The neck to slide connection is a friction-fit, which I did not have any issue with when playing; however, you might want to experiment and add a layer of cork on the male end if concerned with a tighter fit. The horn comes with a used case and mouthpiece(may not be the one pictured). The instrument is not lacquered; therefore, it may have to be polished periodically (we recommend using Weiman METAL Polish). This is a great horn in very nice condition.It plays nicely, with good power, good intonation and bright tone. Thanks for looking and check out our other items! The item "Silver USN 1919 Buescher Grand True Tone Professional Tenor Trombone" is in sale since Saturday, March 23, 2019. This item is in the category "Musical Instruments & Gear\Brass\Trombones". The seller is "silver_cat_brass" and is located in Carson City, Nevada. This item can be shipped to United States, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, China, Sweden, South Korea, Indonesia, Taiwan, Thailand, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Bahamas, Israel, Mexico, New Zealand, Singapore, Switzerland, Norway, Saudi arabia, United arab emirates, Qatar, Kuwait, Bahrain, Croatia, Malaysia, Chile, Costa rica, Panama, Trinidad and tobago, Guatemala, Honduras, Jamaica, Bangladesh, Brunei darussalam, Bolivia, Egypt, French guiana, Guernsey, Gibraltar, Guadeloupe, Iceland, Jersey, Jordan, Cambodia, Liechtenstein, Luxembourg, Monaco, Macao, Martinique, Nicaragua, Pakistan, Paraguay, Uruguay, Canada, South africa, Colombia, Barbados, Bermuda, Cayman islands, Sri lanka, Maldives, Oman, Reunion.