There has been some talk questioning the time table of the making of 'Live 1975-85'. They seem to doubt Clinton Heylin's published works, ‘The E Street Shuffle-The Glory Days of Bruce’ . This is from another book, 'Bruce Springsteen FAQ - All That's Left To Know About The Boss';
In November 1985, just weeks after the 1985 tour was wrapped, Jon Landau sent the Boss a tape of four live recordings—including “Born in the U.S.A.,” the recent “Seeds,” “The River,” and the Edwin Starr original, “War” as part of a proposal for a concert album. When Springsteen went back and listened to a 1975 performance of “Thunder Road” recorded at the Roxy in L.A., he finally began to seriously consider an official concert record and went as far as pondering it as a double album. As with any project that bore his name, Springsteen obsessed over the live album, which quickly ballooned to five LPs and three CDs. He would listen to dozens of takes of each song in an effort to find the best possible version. From there, he would add overdubs with the help of Chuck Plotkin. Finally, after eight months laboring over the music, he handed it over to Bob Clearmountain to mix. But the packaging still occupied his time. According to one report, the Boss sorted through ten thousand photos in an effort to compile the art for the planned sixty-two-page accompanying booklet.
So according to these published sources Bruce received the 4 above tracks.. say November 10th. Bruce started giving the idea serious thought and got to work, right after the holidays, November-December of 1985. That took 2 months, Six more months putting the tracks together brings them until the end of June 1986.