I believe it is a matter of record that Glenn Miller was flying in 44-70285 when the aircraft was lost over the Channel. He was on the passenger manifest for that aircraft.
Joe Baugher's web site has this:
44-70285 (MSN 550) Delivered to USAAF July 5, 1944; Newark, New Jersey July 5, 1944; shipped to the 8th Air Force, England July 14, 1944; 35th Depot Repair Squadron, Abbots Ripton, Cambridgeshire. Disappeared over the English Channel on December 15, 1944 while en route from Bedford, England to Paris, France. Band leader A. Glenn Miller was lost along with the pilot John Morgan and Lt. Colonel Baessell. The pilot departed Abbots Ripton at about noon on the 15th with orders to pick up his passengers at Twinwood Farm, a satellite to RAF Cranfield, located three miles north of the centre of Bedford. After picking up Lt. Colonel Baessell and Major Miller, it departed for Villacoublay, France in marginal conditions, with Bordeaux being the aircraft's ultimate destination; Villacoublay was located some ten miles southwest of the centre of Paris. The aircraft was never heard from again. It is believed that the plane was lost by straying into a forbidden zone in mid-channel which was designated for the jettisoning of surplus ordnance. On its east bound channel leg the Norseman flew directly under 139 RAF Lancasters flying in the opposite direction. The Lancasters were returning from a scrubbed mission in France and were ordered to dump their bombs in the water. Two airmen, both now deceased, witnessed the accident. The Lancaster's navigator had never witnessed a bomb drop on any of his missions and changed positions to see one. He said "I had never seen a bombing before, so I crawled from my navigator’s seat and put my head in the observation blister. I saw a small high wing mono-plane, a Noorduyn Norseman, underneath. I told the rear gunner there's a kite down there. There's a kite gone in! and he said he saw it too."
1944 USAAF Serial Numbers (44-70255 to 44-83885)
We can go back and ask Spragg and Baugher for the sources they used, but I feel confident that both researchers were working from reliable sources and am willing to accept that 44-70285 is the right airplane and that the colors Spragg indicates are correct for the aircraft at the time of the flight.
Don