These are old, unreleased sketches from Yoh Yoshinari (GAINAX/Trigger ace animator). Someone was--and probably still is--selling xeroxed copies of a set of his rough drawings. The original seller titled the collection アニメーター・吉成曜 らくがき・イラスト集(90年代後半頃?)エヴァンゲリオン, or "Animator Yoh Yoshinari Sketches and Illustrations (late 90's?) Evangelion". I don't know how the seller got their hands on all this as-yet unseen material from the 90s and early 2000s; it's possible that these were outtakes from Yoshinari's officially published rough sketches book from 2013. As far as I can tell most of these legitimately seem to be his drawings.
Unfortunately, the photocopies were of low quality and a lot of information has been lost. Aside from some cleaning, the drawings are more or less as they appeared physically. It seems the earliest drawings are from 1994~1995; some genga from Evangelion and Metal Fighter Miku confirm this. At the latest there are his character designs for Grandia 3 (2005), and some work from Mahoromatic (2000); the majority of the set is likely from between 1995 and 2000, though.