TromboneChat

I was recently given a King 3b of some sort, its serial number is 454501. I have looked for a comparable horn online and haven't found anything. Looking to possibly insure it and I am wondering exactly what it is and its value. It is a close wrap 3-B in silver. The bell is engraved with:
"KING"
"3-B"
"Concert"
"King musical instruments"
"Eastlake"
"Ohio"
The number on the slide is 454501, and the number on the rotor is 220. Thank you for any help!

1969 King 3B with F-attachment

The silver plate adds a bit to its value, I think, due to there being very few of them around. Kings from this era are generally very good.

Prices might range from $600 for a beater and $1600 for MINT condition example.

King Trombone Serial Numbers

Serial Number ....... Date
1 - 50,000 ............1893 - 1915
50,000 - 78,000 ..... 1915 - 1925
78,001 - 126,000 .... 1925 - 1930
126,001 - 161,000 ... 1930 - 1935
161,001 - 220,000 ... 1935 - 1940
220,001 - 275,000 ... 1940 - 1945
275,001 - 305,000 ... 1945 - 1950
305,001 - 340,000 ... 1950 - 1955
340,001 - 370,000 ... 1955 - 1960
370,001 - 406,500 ... 1960 - 1965
406,501 - 457,600 ... 1965 - 1970
457,601 - 511,750 ... 1970 - 1975
511,751 - 850,975 ... 1975 - 1980
850,976 - 906,859 ... 1981 - 1982
906,860 - 976,571 ... 1983 - 1984
976,572 - 999,999 &
100,000 - 159,464 ... 1985 - 1986

I owned a late 70s silver plated 3B-F for several years. It replaced a straight 3B. For me, the silver horn was the better of the two in terms of sound quality and response.