I read those stories when DC reprinted them, in serialized form over several months, in various DC 100 page Giants of the time. It was my first actual exposure to the idea that, outside of JLA and the team up books, it really was a shared universe. Those stories were a lot of fun.
I always liked that on the DC side (as opposed to Marvel), there was continuity, but it was more loose. Where characters like Deadman or Spectre or Kirby's THE DEMON, or Cain in HOUSE OF MYSTERY largely existed in their own world, but it
could be expanded in certain stories to allow characters to have shared adventures.
And there were largely separate universes within the larger DC universe, such as Earth 1 (Silver Age JLA), Earth 2 (Golden Age JSA), Earth X (Freedom Fighters/Quality comics heroes), Earth S (the Shazam characters), and so forth.
For me, CRISIS in 1985-1986 killed what I loved about the separate worlds within the larger DC Universe, and brought a smotheringly retentive level of Marvel-style continuity I found offputting and made me less interested in DC titles, from 1986-forward.
You and I read the Zatanna stories at the same time in those 100-page issues.
In order, the reprints are:
1. HAWKMAN 4, Anderson p and i, 13p, Oct 1964 (r in SUPERGIRL 5, Jun 1973, 8 pages of the original 13p story, the only r with pages deleted, and the only Zatanna r not in a 100 page issue)
2. DETECTIVE COMICS 336, Moldoff/Geilla art, 15p, Feb 1965 (r in DETECTIVE 439, Mar 1974)
3. ATOM 19, Gil Kane/Sid Greene art, 25p, Aug 1965 (r in DETECTIVE 438, Jan 1974)
4. GREEN LANTERN 42, Gil Kane/Sid Greene art, 23p, Jan 1966 (r in SUPERMAN 272, Feb 1974)
5. DETECTIVE 355, Infantino p and i, 10p, Sept 1966 (r in DETECTIVE 439, Mar 1974)
6. JLA 51, Sekowsky/Sachs art, 23p, Feb 1967 (r in JLA 110, Apr 1974)
Only the SUPERGIRL reprint did I not read when it first came out. What kids in 1964-1967 had to wait years to read, we got to read in about 4 months across the various 100-page reprint issues, in Jan-Apr 1974.
All 6 reprinted in the ZATANNA'S SEARCH trade collection, 30 years later, with better offset printing.