Maybe you could drag out a magnifyer (10x , if you've got one) & see if you see the typical 'dot patterns' in the colors/etc. that are present in lithos & such .
Don't really think your items represent the same era as the ones in your posted links , greenacres ....
Yours look late 1940's to maybe 1970's to my eyes , but would be nice to find out if they are indeed woodblock prints , which carry a bit more value than plain ole lithos/prints .
Not unusual to find an artists' "chop" on true woodblock prints (or a sig , sometimes in kanji) ... I didn't look close enough @ your images to find any though ....
