Little confused, the "old" panels & controller are just something you've owned for many years but never installed ?
Either way, there are a lot of good Threads on Solar - this one has a couple links I think you'll find interesting - Info (IMO) that should be taken into consideration prior to proceeding (Several members here have great input & perspective which curtailed my initial plans a couple years ago).
If you have the resources to uggrade, I would! Lot of the technology has changed considerably, and maintaining the battery bank becomes one of those critical necessities.
***I would also encourage you to include a suitcase panel hook-up as you proceed with any upgrade. Panels fixed to the roof only
benefit you while your parked in the Sun - do little for you while driving since the alternator shoulders that responsibility...and they are no good if you park in the shade. A suitcase with a long cord starts as a contingency plan - one you'll find quickly becomes your primary charge source (or a great supplement to whatever sun you get from the roof).