i was always starting from the 'diamond' shaped seatstay top reinforcement as a Gitane signifier.
(with exceptions, of course)

to my 'untrained' eyes, the frame looks 80's Japan-made
with its typical mixture-hybride-mish-mash of all different kind european signifiers details.
(shown across lotta major brand names).

i mean, regardless, it will come out a beautiful project for sure.
"versatile" to any components group in terms of style or functionality,
therefore easier to find the right components—when determined— right?