My late build (October 1993), L5000 has a single piece maple neck/board (not a separate maple fretboard mounted onto a maple neck). I believe this has been typical of G&Ls since the beginning, but I could be wrong.
For the string spacing concerns. It will either bother you or it will not. One way to find out. I find the L5000 to be comfortable. Not as comfortable as my other G&L 5 string basses, but definitely comfortable.


