I'm looking for tuners and a tailpiece for a Chubby Jackson 5-string Kay.

Are you looking for a set of 5 string tuners for a bass with a high "C", or for a lo "B"? (In other words, which side has the 3 tuners?) I would suspect that the Kay would have used a set designed for high "C" (with 3 tuners on the left for E-A-D and 2 tuners on the right for G-C). If that is the case, I have a very old set, which needs to be cleaned up a little, but they will work fine.
However, if your bass is tuned like mine (see my picture), this is for a lo "B" (2 tuners on the left) and the spare set that I have will not work very well in that mode. (They break the "B" string, because of the bend angle at the nut).
I will make you a Great Deal on them if they will work for you.
Jon