Bit of a stupid question here .... I take it you can sign write your van etc if its on lease ?? ... what happens when you hand it back and how dies the mileage and excess mileage work charges etc..
As your contract is all based on depreciation, you will get penalised with high mileage charges. 5p a mile does seem rather cheap, but 12k over mileage is £600.00.
Most finance houses used to renegotiate the deal toward the end of the contract if you contact them. So yes, your final few payments would be large payments, but was cheaper than paying the excess mileage at the end of the contract.
You need to ask all these questions before you sign on the dotted line.
Of course, if you have contract hire with maintenance included, they will be on to you as quick as a flash if they see you are doing more mileage than contracted to do.
Most important is to get a booklet on how they judge "fair wear and tear", read it and understand it. It was these charges that the finance houses would make their money. Some contracts, such as a finance lease without a final balloon payment, don't have fair wear and tear worries. You end up paying the full value of the van, so whatever it fetches as a tradein is for your pocket or to put toward a new van's initial payment.
Signage is now 99% vinyl so a hair drier or steam cleaner will get the letters off. You may have to teecut the paintwork a bit though.
Any holes in the floor securing a tank down can be filled with blank rubber grommets. I would lift the plylined floor before fitting the tank (leave plylinned sides) and then refit it at the end of the contract.