All Glories To Srila Prabhupada, the 1968 and 72 Editions of TLC are the same. After that (1974) many changes took place. Srila Prabhupada didn’t really like those changes and wanted that the original TLC be printed again. That didn’t happen and now we have over 1,108 changes in the TLC. In other words the whole TLC was re-written.