This one's a bit slippery - As with all things gypsy, use consecutive downstrokes when ascending strings (I'll be covering this and other aspects of gypsy picking/technique soon).
As for what's going on - This ii V I is interesting for two reasons.
Firstly Moignard here approaches both the Em and the A7 from the perspective of the A7. This can be a useful way of approaching progressions you are familiar with, to avoid 'painting by numbers' and sticking to accompanying harmony solely. You can extend this idea by approaching chords before they change, or purposefully avoiding resolution, amongst other techniques.
Secondly - The line features a harmonic superimpostion, something Moignard does a lot, which isn't that typical in traditional gypsy jazz. While he starts with an A major arpeggio, he changes to an Eb major Arpeggio on the third beat of bar one. While the next few notes tell us he's using the altered scale (A altered here) as a basis, using major arpeggios a tritone apart like this can be a good way of getting that altered sound, without sounding 'scalar'. Give it a go!