I think you're on the right lines, and have obviously been doing a lot of the right kind of work.
(Personally I would always refer to Django for this stuff, and not any of his followers, however good. It's a question of how "authentic" you want to sound, or whether you feel it's OK to let the genre mutate and develop, if later players add ideas and expand on it. It's one of those tricky questions in jazz: you want to learn the rules of the genre, because you love the sound, but at the same time jazz is about moving forward all the time, not preserving the past in aspic. It's a difficult balance, because on the one hand you can be disloyal to the memory, or plain wrong genre-wise, while on the other you can too hidebound to the past. In a sense, gypsy jazz is perhaps better treated as a folk music - with traditional idiomatic moves handed down and preserved as well as the ear will allow - rather than a form of jazz, which ought to have given way to the next movement by now.)
Anyway...
You sound like you've got much (if not all) of the essential language. What I would do is stop looking for more scale or arpeggio formulations, and start to look at phrase construction and melodic-rhythmic ideas. (IOW put down the microscope.

)
Note-by-note transcriptions of Django ought to be top of the list here (IMO) - but don't analyse them in terms of scales and chords, so much as rhythms, melodic intervals, articulations, etc.
Even with very limited raw material (eg dim or m6 arps), there's a hell of a lot of melodic invention you can do. One simple strategy I'd use (and I was lead guitarist in a Django band for a couple of years, albeit not a terribly successful one

) is to include a lot of chromatic moves, beginning with half-steps below chord tones. I always used to work from the chords, adding easy pentatonic notes and chromatics, and never really used scalar playing. (I didn't think of it that way anyway.)
I didn't copy Django solos, and the only one I remember transcribing in full was "Undecided". But I copied enough (I thought) to emulate his feel. I "got the vibe", and followed that using my intuition. We weren't exactly aiming at pure authenticity (the rhythm player in the band had built his own Maccaferri copy, but I just used a standard Guild F30), and we weren't playing to committed gypsy jazz fans. We just loved the music, and did what we could.
PS: my avatar is Django's left-hand, showing him having a joke with the photographer. (I like to remember not to take this stuff too seriously,)