My fuel gauge seems to have gone tits up. I found another gauge but it's off of a newer second gen and says "unleaded fuel only" on it. Can a run of the mill DIY guy like me pull off the face and swap it! This is the small 2" stock 1973 gauge.
The hard part is pulling the needle off, and putting it back on (It's not indexed). I'm sure the pros have a better way to do it, but I just pinch it with my thumb and index finger with even pressure on each side. Sort of pry it off with your fingernails against the gauge face. It may take a fair amount of force. It must be pulled STRAIGHT off. It's a bit risky.