One can clean up the wire quite easily to solder , copper naturally oxidizes and relatively fast, regardless of the heat shrink etc, oxygen is present at the solder joint and the oxidation works its way up that jacket. You'll notice as you strip it further, it is clean.
The bigger issue here to consider is that as vinyl ages it becomes hard, which equates to loss of flexibility, neoprene does not age this way. Neoprene is also non corrosive and chemical resistant.
With that in mind, I've been looking to rebuild a pedal board I made in the late 80s, and of late have done so much reading on newer cables being this or that, which for the most part is snake oil as the human ear can not detect a 5% difference in tone which if one digs hard enough, they will find some honest tests and specs on these expensive cables is exactly what separates most brands, if they even post true cable specs.
I've come to the conclusion that I will use Hosa straight 1/4 plugs to connect my pedals , so as to eliminate cable between pedals [ no offset jacks] and will use either Belden 8412 mic cable to start/end the chain under the board as well as tie to the Switchcraft 1/4 female jacks mounted on the side of the board. The idea is to have as little cable period , and have as little of it showing as possible.
I have considered trying Lava Magma but have yet to find it in bulk, a few feet will do me whatever I end up using.
I run to rows of vintage BOSS pedals, one row of analog , the other digital , Via [2] PSM5's so I can make any combination I want as the rows are Y'd together. I know I could use a voodoo power block or some new fangled power supply, but this has served me well.
Anyway, unless you are playing through an ultra clean linear amp, you will never begin to hear the difference of George L versus a Belden cable, Especially once any gain/distortion is applied.
Then again, tone is subjective and we all perceive sound differently, but a good advertising/marketing placebo usually prevails
