I own a King "Duo Gravis" 7B Bass Trombone. I bought this horn new in 1975 and played it for approx. 2 yrs. I am wanting to possibly sell it and do not know what horn would be comparable to it for setting a price. I am not out to pull teeth but do not want to give it away, either. It is in what I would consider very good to excellent condition. All tuning slides work, rotors are free moving,slide is smooth and it is in the original case. It has minor dents,lacquer spots, but overall finish is in good shape. I think I may even have the keys to lock the latches but I am not sure. I would appreciate any help or suggestions. Thanks.

Hallo,
I am interested in your King 7B bass trombone. Is it gold or silver brass? Where do you have this King?
You can contact me by mail: zvukobraz@gmail.com
Can you sand me pictures please? Thank you very much and looking forward answer.
Have nice times
Zdenek Nemec