After making it's way through many owners, I have been graciously given a Hofner guitar. It looks like the Club 50, but the headstock, fret inlays and pickguard are mother of pearl. There is a good chance the electronics don't work (It's been misused for at least 40 years) but I can't get that far; my amp lead doesn't fit in the plug. The plug is too small.

What's happening? I'm young and naive, was there a different type of amp connection 40 years ago? And can I get an adapter?

Thanks in advance.