An ambitious project (seemingly) just getting started:
https://redwing-copter.com/menu-1935/
Promising a great deal (perhaps too much), but having just bought the Boeing 247D, and idly thinking about reliving some old Imperial Airways routes (although they never had this aircraft), I'm intrigued by this... Even with a few recreated airports this could be a lot of fun. There's already a freeware Croydon Airport on flightsim.to. With a Le Bourget and Amsterdam Schiphol to go with it, that'd be a pretty good start
