Introduced by Martin in 1931, the D-28 is prized for its booming projection and high quality tone. First made with brasilian rosewood back and sides and then with indian rosewood starting in 1969.
 
This one from 1977 has been used for the last 20 years by a guitar teacher. It has been played regularly which gives it this mojo.
A Fishman pickup system has been installed which allows to play it on stage easily. volume & tone control accessible on the side and jack connection on the bottom strap button.
 
Structure is good and solid. Comes with original black plastic molded Martin hardcase
 
Back and sides : Indian Rosewood
Top : Spruce
Serial : 394523
Pickup system : Fishman
Controls : Volume and tone (separated bass & treble)
Case : original Martin case