Flywheel!

Help! Just got my engine back from the guy who's rebuilt it, looks great until I discover he has misplaced the flywheel,
And to make matters worse, says he never had it( argument looming!)
Having spent a fair bit on a new 85 cc head and barrel, and replacing a kick shaft cog, feeling a bit pissed off.
Can anyone tell me my options on getting this motors spark, and lights???
It is a 1973 6 volt st 70/85! ( hitachi )

If it's the flat Hitachi flywheel,
that exact same flywheel is your only option.

Aside from a small piece that converts the S-tap into a 12v tap...

Anyone got one??????