'Warplanes of the Third Reich' by William Green, line drawings by Dennis Punnett?
Doubleday 1970. Detailed 3 views of evey single plane from biplane to 4 jet bomber prototypes, sketches of every variation, and a flight history of most of the prototypes.
Not to mention color heraldry and camoflage foldouts of versions each of bf 110, ju 88 (18 examples),me 262, do 217e,ju 87b, bf109e,he111h.
I just found mine where I lost it several years ago (right in the bookshelf).
Probably averaging 4 photos, drawings per page over 670 pages.
Anyone ever hear of a Siebel SI 201?
Single engine pusher with a variable incidence WING which was to compete against the more famous fieseler Fi 156 for light observation plane.
Looks like a trolly car with a sweptwing stuck on and a corrugated boom to the tail surfaces.
Now THAT looks cool.

(from the web)
A LOT of planes I never heard of. including the ultra cool HE 119.
If you don't have it, and you are interested in it, keep a lookout on ebay and amazon, better yet, look at the local library.