Page Publications' digest-sized Werewolf By Night #7 was published in 1981:
The cover is from Marvel Comics' Werewolf By Night #20:
The contents are as follows:
Vampires on the Moon!, originally published in Werewolf by Night #19, July 1974
Eye of the Wolf!, originally published in Werewolf by Night #20, August 1974
One Werewolf's Cure... Another's Poison!, originally published in Werewolf by Night #21, September 1974
This issue also includes black and white prints of the relevant front covers.
This is the cover to Werewolf By Night #21 without the Marvel comics trade dress and price and issue number boxes:
The final page includes this cover, also without trade dress, caption boxes and price and issue number boxes:
Compare this to the cover of Werewolf By Night #19:
The GCD indexer notes that this cover has alterations to the faces of Werewolf and Dracula. It is difficult to be certain if the Yaffa edition is substantially different to the Marvel edition due to the reproduction quality, but it does appear to me that the eyeballs on each face are different, and the linework on the Earth in the background also appears to differ. Similarly to query over the cover on Yaffa's Werewolf By Night #8, I'd like to see clearer prints of the Marvel pre-production covers in order to make a firm call either way.