Thanks, Michal! This looks like a super casting from a very interesting kit. And thanks to AndersN, a member of the
Large Scale Planes community, for the photos.
The 129 suffered from slow speed and a lack of protection, so less than a 1,000 were built, but that's all the more reason to have a top resin kit, as styrene companies aren't likely to go down this route.
And with plans already announced for the B-3, the airframe gets VERY interesting: it initially started out with the 2cm FlaK 18 cannon (ala the Stuka), but was later adapted for use with an aircraft-adapted PAK 40 75mm! Talk about cool stuff.