Wow, really great score, even tho it looks like it's been sitting many years!! Yes, try to save the wiring cuz it is 1968 WAGON only...........even the 1968 Sedan harness is on its own!! I have a 1968 dash harness, but it is for a Sedan!! You can use "donor wire" sections from any 68-80'ish Datsun parts car wiring cuz basically used the same color codes. Vintageconnections.com will have some of the white plastic plugs, but some of the 1968 might be different..........all you can do is search that website for pics & match up, don't think they can tell you what to buy! You can buy a 1968 WAGON wiring diagram from a guy named Paolo at firstname.lastname@example.org .........do this.......it's the only way to figure out electrical messes, unless you have LOTS of patience!!
This is the place to be to find answers!!
PS please PM me if you have other questions or comments, cuz I don't get email notifications from Ratsun, and I don't get to this forum section very often!