The mark "->" or "<-" means that the plane was flown by Geschwaderkomodore (unit commander),then the second dash ( following the Balkenkreuz) indicates the Second Gruppe.
The Bf109 E4/N was flown by Gen.Adolf Galland (major and then oberstleutnant) the JG26 commander and one of the best Luftwaffe experten (aces).
I voted paper just looking at the first post. But having seen some of the close up shots now, I do not think it is paper. Never having seen a paper kit, I would think that embossing the paper to make panel lines and whatnot would likely be cost prohibitive.
Sooo... hmmm. Not sure now. The engine detail is pretty crude. Not plastic. Maybe wood or resin.