I take Trevor's point, but if it were mine, I would take it that with 7000 miles recorded at the time of sale, the dealer should consider that it does not need servicing when you take delivery. It will however then require a service when you reach 10,000 miles.
Boiled down:- dealer services it (early) before you buy, then you need to have it serviced at 17,000.
Dealer doesn't service before you buy it, then you need to service it at 10,000.
I guess the 10,000 mile interval will be that or 1 year - whatever comes first.
I think if I were buying then I would opt to let it run to 10k, and then have an arrangement with the dealer to return it for a free service at the 10K.
Kind regards,
Gareth.