After many years of having a rattly shifter in one Sprite, I just found out that there are 2 different shifters.
One for the smoothcase, one for the ribcase. And the rib is 1/16" longer between the balls. I stuck a ribcase shifter in a smooth case and could not shift because the shifter was too tight. After all the fussing and research I find out about the differences. Now I know why my other Sprite rattled and why my current Midget doesn't shift. Too bad I sold the other Sprite before I knew this as the new owner and I could have swapped shifters and we would both be happy.