But that
is an Adamski saucer, just with German markings (and added guns)!*
Oddly enough, I only yesterday ordered the Wave Models 1/48 Adamski Flying Saucer from Hobbylink Japan. Mine will be piloted by Daleks, rather than Nazis.
http://www.hlj.com/product/WAVHH-41/SciThere is also a 1/60 version (6 inch diameter), from Atlantis Models.
http://www.hlj.com/product/ATL1004/SciBoth of these are injection moulded plastic kits.
Of course, if the original was actually a hub cap, these scales don't mean much.
*
Edit: oh, I understand now. The linked review says that there are two versions of the Hand & Head kit, one labelled as a 1/72 Haunebu, the other as a 1/48 Adamski saucer.