Ha, I've just found this in my notes to the first Mirwood CD, so I knew about it but didn't fully appreciate the differences.
"Mirwood then made a mistake with the next single, and instead of going with one of the new songs, plumped for the remake of ‘The Bounce’ backed with their version of ‘The Duck’. It failed to chart and by the time their next single came out in early 1967, the damage had been done, despite it being the excellent double sider ‘The Same Old Thing’ / ‘I’ll Do A Little Bit More’. A Mirwood release sheet of the time had ‘The Same Old Thing’ listed as by Walter Ward, the group’s lead singer and in fact the only member on the recording. It was to have had an instrumental version of the song on the flip by Walter Ward’s Band. Though that wasn’t as imaginative as the eventual release, it would have gone down a storm at the Casino! Some copies of ‘The Bounce’ single are actually an alternate, sparser version of ‘The Same Old Thing’, which certainly wouldn’t have helped it to sell either."
The idea of a vocal / instrumental Mirwood release as by Walter Ward instead of the Olympics is fascinating too. And it was covered in a contract for another two Jackie Lee titles Tin Pan Alley and Anything You Want, Any Way You Want It which of course were unreleases till Soussan booted the second as I'll Do Anything and we put out Tin Pan Alley on our Jackie Lee "Mirwood Masters" CD.