To me
in addition to all engine and prop logs starting with the overhauls.
suggests that engine and prop logbooks are available only starting
after the overhauls.
One still needs to get back to where the hours became mismatched. Was it a crash or a prop strike?
Anyway, all this will be obvious when you visit the aircraft and see the paperwork.
£50k is probably a fair price for an old Aztec - if everything on it works. Low-end piston twins tend to be worth more or less just according to the remaining engine hours.