Is there a way to verify how rare a kit is?

[Draggon]

Or just plain over the top with some Richard Carroll tires

and better rear suspension. Is there a source of those tires? ( Okay so I'm old and I remember those things).
 

 

 

 

 

 

 Someone cast up those tires in resin. I've seen them twice on ebay. The orginals pop up too, although very infrequently.