The best place to ask about this is here:
http://www.ibanezcollectors.com
However - the advice will be to keep it as original as possible. Why do you feel the electronics need to be replaced? If the pots have become noisy, a squirt with contact cleaner spray will probably sort them out, if the jack connection's loose & crackly, clean the contacts with some abrasive paper & bend the contact a little so it grips the plug more tightly.
The pickups on this guitar should be Ibanez Super 70s - these are actually highly sought after by Ibby collectors & reckoned to be pretty much equivalent to Gibson PAFs as far as sound's concerned.
Do you know how old it is? The headstock shape suggests 76 onwards, and there should be a serial number stamped on the back of the head - the first letter is the month, the next 2 numbers the year.
What it's worth depends on where you are - because copy-era Ibanez were more common in the US than other countries, they tend to fetch a bit less there. However I wouldn't like to make a specific guess about the value of this one.
In answer to your question - I think changing anything - unless it really needs to be replaced - would probably have a negative effect on both its value and collectability.
Jon.