Antique Mini Trombone Link 18k Gold 20.5" Watch Chain

Era: Victorian
Origin: English?
Material: 18k gold 
Gemstones: n/a 
Dimensions: 21" long, 3/8" wide
Weight: 39.8 grams with T-Bar, 35.3 grams without t-bar
Circa: Early 1900s

Hallmarked "JFK" and "750"