I have an old model minibike that has a 3 hp briggs engine, the finishes are mostly gone and the seat has been modified but I bought it for $20 about 20 years ago. I added a modern coil but can't get the old flywheel to make a spark.
I saw a $2500 very original Bonanza mini for sale with a Tecumseh engine and a Hegar kik start on it. That kik start fascinated me, I don't see any for sale anywhere else. Hegar is still in business selling go kart and airplane brake parts but doesn't have the old tooling, someone approached them in 2013 and they were open to making a batch if someone had a complete unit to work from. It didn't ever happen as far as I can tell.