The year usually comes from adding 50 to the first two numbers of the serial, for this era horn. From the engraving, stamping placement, valve lever and cover, this is a Gen II. 2007 sounds about right. If orange lacquer was used, it might be earlier, but then the engraving might be Abilene style. Orange lacquer was I think 80s or 90s.
Prefix "5" means that horn is from 2000 or a little later. My 88HCL from about 2007-2008 hasn't this prefix, so I think that Conn has stopped use it earlier.
The "serial numbers" on the slide are production numbers so they can match the two parts of the slide to eachother when they get separated. Many makers us a similar system so that all the parts of a horn can be kept together.
The "serial numbers" on the slide are production numbers so they can match the two parts of the slide to eachother when they get separated. Many makers us a similar system so that all the parts of a horn can be kept together.