The story is that the Selmer Charles Delaunay took out to the USA for Django, which became damaged during the trip, was subsequently repaired and sold before he returned to France. He could well have sold the Gibson also.
After he returned from America, Django almost exclusively played an amplified or full electric guitar; the notable exceptions being his reunions with Grappelli. For the majority of this period, it was a Selmer with Stimer amplification that he used.
Here he is playing a Selmer with some unknown form of rudimentary amplification from early 1945:-
