Tis indeed Jock.
I can relate that the Big Hit version of Do It Good is totally different to the Dave Hamilton tape we've got which is earlier 1970ish and more basic funk groove, the 1976 Big Hit version has a storyline lyric. The flip is a totally different song to the ballad coupling we found on the master tapes though both were Dave/Buddy compositions. The 45 is a blues ballad called 'This World Without You', the earlier master is a soul ballad called 'Somebody Is Wrong'. There you have it, the masters will be out on Kent CDs eventually