By comparison, my '76 Plymouth took about 5 years for the dashboard to develop cracks, flake, and transition from “padded” to “crunchy”. The seats lasted slightly longer. '60s & '70s polymer technology was not very robust.
It wouldn’t surprise me if the electronics still worked though. Analog circuits were very robust, not this wussy “keep the cat away from the surge protector on a dry day” crap we have now. The rovers probably also had a warm, full response curve, with a throaty top-end exposing long-sustain harmonics that you just can’t get with solid state. Wait, what thread was this?