David,
Amoskeag had the following sell for $4,025 on 3/26/11
Smith & Wesson Model 56 KTX-38 U.S.A.F. Revolver

serial #K506803, 38 Special, 2" barrel with an excellent bore. This pinned and recessed revolver has 95-97% of the original blue finish remaining with mild silvering on and around the muzzle, edges of the frame, and along the front and rear faces of the cylinder. Additionally, the "U.S." marked smooth backstrap has some mild freckling along its length which is also on the frontstrap. The hammer and trigger have bright color case-hardening with some minor freckling visible. The checkered, diamond-center PC grips are numbered to the gun on the interior and are in near excellent overall condition with some mild handling marks around the butt and some flattening of the points. These revolvers were manufactured in the early 1960’s on special order to specific U.S.A.F. requirements and are a true rarity with almost all of the 15,205 gun production run destroyed by the government. This example is in fine overall condition and would make a great addition to any U.S. military or Smith & Wesson collection. (74108-15) {C&R} (3500/5000) SOLD FOR $4025.00