ALL The Shadow issues from the 70s?
Nope. Just the ones by Kaluta. (A gross disservice, as those Robbins issues are actually not half-bad)
BTW, the ones from the 80s remain largely uncollected as well. The 4-issue mini by Chaykin has a TPB (Blood & Judgment) but that's about it. The 19-issue ongoing that came after (along with the two Annuals) has never been reprinted.
Neither was The Shadow Strikes ongoing. (31 issues, plus one Annual)
The Graphic Novel from Marvel (Hitler's Astrologer) was always a HC, though.
Regarding the Dark Horse minis, the first one (In the Coils of Leviathan) WAS collected, but not the other ones (Hell's Heat Wave, The Shadow/Doc Savage, The Shadow & the Mysterious Three one-shot, the crossover with Ghost, et al)