Well.....
If you want to delve into the "Luft '46" realm, than anything is possible.
As for the Treibflugel, I saw some kits in 1/72, 1/48 and even one in 1/32!
The Lockheed XFV was part of a STOL thing going on with the USN - there were others, too, like the Convair XFY.
If you search Lockheed XFV and Convair XFY, you'll find all sorts of kits (like vintage Aurora) out there.