rewire older speaker internal wiring?

Different brands of caps will have totally different sonics.If
you get in there to do it,maybe try Solen first.They're kinda
neutral.There might be stuff on the net telling you what to
expect from what brands in that speaker.Sometimes a cap change
can make it sound like a different company made it.Same thing
goes for amps.I hope this link helps out. Link>>>[http://manuals.harman.com/JBL/HOM/Technical%20Sheet/4311B%20ts.pdf]

Any good wire should be ok.Good tight connections are important.Also,don't use higher uf,or mfd values on the caps
unless a real pro tells you its ok.That will pass lower frequency's to the drivers possibly blowing them.A little higher voltages should be ok.There's a lot of JBL fans on the net that may have places for help.

Another link>>>[http://www.lansingheritage.org/html/jbl/jbl.htm]

Many people experienced in this rebuild will tell you to use a parallel 'bypass' cap of some small value.
Don't forget that caps in Paralled ADD values.

Solon is a good choice as is Clarity SA for more $$. It gets wacky after that and in my OPINION should not be purchased unheard or without a knowing recommendation.

My panels start wit Solon and I am pricing out a new x-over of identical design to original, using Clarity SA. I could spend more $$ on a single Mundorf Gold/Silver/Oil (whatever) than I intend for the entire project!

First rewire the innards...and then I will advise you on the crossovers. If you want my HO that is.