I worked for Charly Records when these were released...indeed I actually compiled the CD in question and sneaked a few tracks onto it that had evaded the LP releases.
The source for these comps wasn't actually Japanese releases. One of the Charly guys (and dare I say the world's #1 expert on James Brown), Cliff White, actually went over to the Broadway Studios (ex Quinvy), met up with Quin Ivy himself and took DAT recordings from the original master tapes. Northern fans (and I know there's a few of you on here!) please note the take we used for Don Varner's 'Tearstained face' is different to the released 45...check out the brass for starters!
But did Quin have any 45's left, I hear you cry...yes a few pieces...and yes I got the copy of 'Tearstained face'.
How did the LPs originally sell...as others have pointed out, not really that well, and indeed the CD didn't fair well at all...dreadful sleeve didn't help at the point of selling in! I still see copies of the LP's over here in Japan, oddly enough...always brings a smile to my face.