I was looking for a discography of the label but found only this thread. These are the ones in my collection. The Mary Lou Williams is my favorite of their originals, and I've never read of it being reissued.
J-1201 Coleman Hawkins All Stars (Emmett Berry, Billy Taylor, Milt Hinton, Jo Jones, Eddie Bert)
J-1206 Mary Lou Williams -- A Keyboard History (Wendall Marshal and Osie Johnson)
J-1208 Max Kaminsky and His Windy City Six (Pee Wee Russell, Miff Mole, Joe Sullivan, George Wettling, Jack Lesberg)--Chicago Style
J-1210 Swinging with Ruby Braff (Sam Margolis, Billy Byers, Marty Napoleon, Milt Hinton, Jo Jones) (original session)
J-1211 Jelly Roll Morton
J-1213 Sidney Bechet/Omer Simeon --Jazz A La Creole (Simeon session for Jazztone)
J-1214 Charlie Parker--The Fabulous Bird (reissue of Dial releases)
J-1215 Tony Parenti--Happy Jazz (Red Allen, Tyree Glenn, Hank Duncan, Milt Hinton, George Wettling) (original session)
J-1217 Joe Newman and Billy Byers--New Sounds in Swing (Gene Quill, Lou Stein, Milt Hinton, Osie Johnson)
J-1219 Jazz Concert (Red Norvo, Krupa-Ventura, Teddy Wilson (1945 Town Hall concert)
J-1220 The Count's Men Featuring Joe Newman, Frank Wess, Frank Foster, Benny Powell, Sir Charles Thompson, Ed Jones, Shadow Wilson
J-1226 Charles Mingus, John LaPorta, Teo Macero, etc.--Jazz Experiment (reissue of Period release)
J-1229 Maxine Sullivan and members of the John Kirby Band--Flow Gently Sweet Rhythm (Charlie Shavers, Buster Bailey, Russell Procope, Billy Kyle, Dick Hyman, Specs Powell, Osie Johnson, Aaron Bell, Oscar Pettiford) (original sesssion)
J-1236 Sammy Price in Concert (Emmett Berry, George Stevenson, Herbert Hall, George Foster, Freddie Moore) (original)
J-1239 Bob Brookmeyer--Zoot Sims Quintet--Today's Jazz (reissue of Storyville release)
J-1241 Jimmy McPartland's Chicago Rompers/Paul Barbarin's New Orleans Stompers--Dixieland Now and Then
J-1256 Don Elliott Quartet/Sam Most Sextet--Doubles in Jazz (reissue from Vanguard)
J-1258 Comparative Blues (anthology of other Jazztone releases)
J-1259 Slidin' Swing, The Trombones of Vic Dickenson and Urbie Green (reissues of Vanguard releases)
J-1263 Kai Winding/Sonny Stitt--Early Modern (reissue of Roost recordings)
J-1268 Cootie Williams and Rex Stewart in The Big Challenge (Coleman Hawkins, Bud Freeman, Lawrence Brown, J.C. Higginbotham, Hank Jones, Billy Bauer, Milt Hinton, Gus Johnson)
J-1271 Charlie Mingus--Jazz Experiment (same as J-1226)
J-1277 Cal Tjader Quartets/Red Norvo Trios (reissue of Fantasy releases)
J-1279 Elliot Lawrence -- Big Band Modern (reissue of Fantasy releases)
J-1281 Clifford Brown/Art Blakey--Jazz Messages (reissue of Pacific Jazz releases)