Just look on the cilinders. It'll say wether its co2 or pcp.
I wouldnt be so sure its pcp. Does that cilinder read kohlendioxid?
CO2 you need a master co2 tank. For instance a fire extinguisher.
Be sure to cool before filling.
Yes they can be diverted to air. Mine is pcp now. Costed about E150 iirc.
But I'm not sure I'm very happy with it..
Worth: the CO2 version about E350-500 I guess