local independant or do it yourself, people pay to much of a premium for a dealer stamped book, A guy i know purchased a 2007 bmw m5 fully stamped up book from stratstone bmw 68k miles, i put a new n/s track rod end on it for him, he was slightly miffed that it needed anything doing to it as it had always been serviced by bmw i told him to contact stratstone to see if there was any work outstanding on it, they told him there was £4.5k of work defered on it like discs and bells all the way round plus quite alot of things.
Unfortunatly for him there is little he can do, private seller who sold the car with a fully stamped book has done nothing wrong legally he sold his car with a years mot and recently serviced so fully roadworthy at the time even the private warrenty he got won't cover any defered work so really a dealer stamped book is worth no more than an independant. more important than pretty stamps in a book is a workshop jobcard for every workshop visit to verify what was done and what was defered. how many cars get sold on the strength of dealer stamps and no supporting paperwork car dealers seem to lose all that paperwork but manage to keep the service book.
As said above if you feel confident enough diy or local independant.