Proof of Purchase is normally the van's original delivery invoice/receipt (for the whole van) - as it covers all appliances/fittings installed within it.
If its a Jayco van, we don't need the proof of purchase, but the CHASSIS # must be filled out in previous section.
If the issue is with an appliance/fitting that was installed after market, you will need to provide the proof of purchase (receipt) for the individual item.