Is Jaco more of a bass player icon that might not have had the wider recognition?
Those two 1970 Js would, I imagine, have been custom orders. There is certainly evidence of fretless Jazzes (& Ps of course) before 1980 so they have been quite niche and only really got going when Fender moved production back to the US after the success of the MIJ/CIJ basses.
Still no clearer on the p/up placements though.