Helpfully, Ibanez has removed all their wiring diagrams pre 1994 from their website. If anyone has a diagram for a 540S7 please can you let me know!
I've got a few, I'll see what i can dig up. It's just a standard HSH with a 5-way, Volume and tone, right?
This is the diagram I use for my RG570, HSH standard.
This is the diagram for the nicer-ish Ibby 5-ways, where the middle pickup is actually a stacked humbucker, like the UV777s.
If it has one of the older-style 5-way switches, like strat-style, this is the same as the first diagram, but with a different switch. (diagram from an old JEM)
If you need a custom diagram or anything like that, tell me what you want in each position, and what controls you want, and I can draw something up.
Hope this helps.