Bach LoyalistThis are the most commonly seen vintage brands, obviously not a complete list. Holton Loyalist website:Vincent Bach is on back of handslide cork barrel, earlier models also had on back of outer handslide, bell sections not serialized. White eraHolton is usually on neck reciever.

Here is a website dedicated to King tromobones from the H.N. Neck Receiver, Earlier models also tuning slide. You can find more helpful information on the Conn Loyalist WebsiteKing (Pre UMI Era) Outer handslide two places, below cross brace and lower cork barrel.

Here is what we have seen at our shop by brand/maker:Conn (before 1970) Handslide Tennon below threads, outer handslide (lower outer tube at the top in back), No serial on Bell section, but model number is on bell. White Era will often have the serial number on the tuning slide, but not always. Sometimes the serial number will be on both the handslide and the neck receiver. Trombones will have the serial number either on the back of the hand slide or on the neck receiver where it attaches to the handslide. Vintage Instruments can usually be dated by serial number.

C g conn trumpet serial numbers