Modern Vespa

Unfortunately my piston in my Pk100s engine in my vespa 90 smallie has a noticeable indent and crack on the side a cm down from the piston rings, however the cylinder is still in tip top shape, is there any replacement pistons comparable for this model being sold?

On another note how much side to side wiggle of the crank arm is acceptable?

Thanks for your help

Add a picture. Might be able to save it

Ah I forgot to add photo, there is a slight build up of carbon in the area due to slight depression. If it's unsavable I seen that Sip recently released a 125cc kit that matches the Pk100s case exactly with little modification apart from mabye reinforced clutch spring.

The engine was running perfectly but only discovered once opened up, previous owner has not done much maintancence.

I think the previous owner has been having a good play with it. You see it has 2 thin piston rings in each groove. This is so it revs higher. Fine as long as the lower in each, doesn't jump the peg
That piston damage was done when it was on the bench (more likely floor). It's Unlikely to make any difference as it's been running a while. Drill a small hole in each end if the crack to re use it. But I'd be splitting the engine to see what other surprises were in there.
Would guess this whole scooter looks like its had a hard life.

Thank you, yes this engine did have very strange modifications I'm very confused about. As long as there is no like jb weld in wierd spots or machining inside the case it should be fine as il be able to replace things, also the vespa 90 it was on is in good shape.