Well, there are a few harnesses you're talking about here...
1st of the all, head-lights, turn signals for the front, fogs, wipers, ect, are connected to the Engine Bay Harness, which is part of that fuse box in the engine bay. That ends in a Huge Rectangle-shaped "Super Multi-Position Connector" or some such nonsense, that allows the behind dash harness and rear chassis harnesses to connect to it...
The White and Grey Connectors in here...
Here is how the Bay Harness mates up, note the fuse box in the bay at one end and the square white jumper at the other...
There is a grey box for the rear-chassis harness that connects to the behind dash harness as well. Now, each one was different according to ProjectRDM.
My best guess/suggestion would be to use the rear chassis harness from the 1997 and the front from a 1997 so all your kouki things light up right, at least that sounds like the easiest path, since I can't comment on individual differences between harnesses and years, but the 1995 and 1996 were different from each other, and the 1997-1998 were the different from the rest but the same as each other.