Looks like an Aero 30 Roadster, built from 1934 to 1947, with a non-stock convertible roof to me.
That's the right car, yes, but doesn't solve the puzzle!
I had to be careful what I asked for without giving the game away, hence I only asked 'from when does it date'. The
base is from the 1930s, yes, but that's not the whole story; this puzzle is therefore locked for you to look into and come up with the full answer!