How to remove sticky residue on vinyl upholstery?

I recently bought a vintage 60’s black vinyl sofa for my new place, and was astounded by the condition- not a rip, nick, or loose stitch on the thing. But when I removed it from the house I bought it from, I noticed the backside of the couch, and the sides had a sticky residue. I’m guessing those parts were never really cleaned or touched since the thing had probably been in the same spot for 40 years. No problem I figured. I tried my usual cleaners and de-greasers that are safe on vinyl. Nothing. I tried Murphys, I tried white vinegar, I scrubbed and soaked, still there! I have yet to try some very diluted Goo-Gone. My friend told me the vinyl may have broken down and there may not be any hope, short of cleaning and re-sealing the affected areas, which luckily will hardly be seen. Just what I need right now- another project. I know I’ve seen this same sticky film on old vinyl car interior parts, so I figured I’d ask here to see if anyone has any proven methods of fixing this, or if I should just give up. Thanks!

careful you don’t lose the color

Simple. Use Goo Gone.

Have you used goo gone on dyed vinyl?

no, but ive used it on just about everything else including the paint on my cars, have never had any problems with it. It is nontoxic and from what i understand an all natural concoction. I would simply use a wet rag or fsoft towel and rub lightly and see how it goes, i would bet you’d be fine.

I worry about goo-gone, as I know it will destroy a lot of materials. If I used some I’d dilute it a ton and use in in an inconspicuous area. Just have to pick some up.