P.P.S. this album entered Billboard's top 200 album chart at #189 in the issue dated 17th August 1974, where it is listed as being available in all 3 formats.
P.S. the package is missing the "(W) A Warner Communications Company" text that came into use across the whole WEA group of labels in 1975, so that also points towards this being a 1974 release.
Schwann catalogue for December 1974 lists this as being available on LP, 8-track and cassette, as do subsequent issues I have from October 1975 onwards. No release dates are listed, so it is possible that the July release was LP and 8-track only, with cassette following shortly afterwards. It is also possible that Atlantic gave Schwann incorrect release information - I saw this happen a few times with proposed new releases being cancelled after Schwann had gone to print (a few on ABC-distributed labels in late 1974 and John Fogerty's infamous HOODOO on Asylum in 1976 come to mind).