Quoted from marschner:Is a cabinet with original faded sidearts better when selling than putting on new decals?
It should be noted that that era of WMS/Bally games did not use cabinet decals, at least not until Monster Bash came out. They actually silk screened directly onto the cabinets. Some cabinets the underlayment still seemed to have some form of a sticker over the wood as certain titles (CFTBL for instance) that seemed to have worse peeling problems where the legs attached.
All that said a collector like me would much rather the original cabinet if possible just because those are more durable than a sticker job, no matter how well it's done. If the fading is really tragic then it might be better to go with decals, but in most cases I'd rather have some fade and a few scratches to not have to put up with peeling decals. YMMV.