(I'm not sure if it's a Model B either) Definitely not, it's too small for a Type B dual-head, although the later ones did have a similar housing. Also not an antenna, there's no reason you'd have a tube open at both ends. I'm with ThatACAGuy. Looks like a Little Giant with a homemade housing. They...
I doubt they're actually selling 2001s. Notice the decals on the rotator have all been photoshopped off. It's more likely they just stole the image, and their actual product is a weatherproof fire alarm sounder.
That must be one robust Thunderbolt. why is it under the rocket instead of in the viewing area or by the blockhouses? It's not directly under. I wish I could find the footage otherwise, but it's actually quite a bit closer to the camera than the missle. You can see it again at 29:12 Telephoto lense...
It's difficult to tell with the size of the image, but it looks like either an ASC E-Class or an ATI HPSS array. They could also be off the shelf drivers for public address use.