No engine spark on small engine

No engine spark on small engine

I’m trying to get my old go-kart running for my son. It has a 1971 Briggs and Stratton engine and I think it may need a new magneto/engine coil. I’m just not sure where to purchase this. I see them on Amazon, but they appear slightly different. Are magneto’s sold today compatible with a 1971 engine? Thanks in advance, Craig