Ok swapped the tin over for mothers California gold pure wax in a red tin.... Says pure on the front but underneath it says caution flammable contains petroleum...? So is this the pure stuff or have I got the wrong gear again?

thats typical Carnauba its used to soften the wax, makes it easier to apply on paint, that is an petrolium is a ingredient for Carnauba waxes on cars. you would find that on any of carnauba soft waxes. again i dont know anything about pinball waxing, so im explaining it on car side as i have a show car, there are hard waxes with no petrolium or silicones you would have to look for natural hard waxes if the aim is to avoid those chems on your pinball. they are getting harder to find as silcones are very popular for cars as natural hard waxes are very hard to polish off after being applied. so somene here might be abble to advise you on if petrolium based waxes are ok? i ont know that but on your question of why is this pure cab wax with petrolium well that is what cab wax has in it. if it doesnt have silicone which is the replacement for petrolium in other waxes.