In some cases locations do matter and it is not the same if the straight truck was maintained at the authorized dealership where they only maintain this brand of trucks or is the maintenance performed in some local no name shop where people have zero experience maintaining this make of trucks.
Once you go trough all of those details check the situation on the vehicle to see that the things mentioned in maintenance plan and service book are really changed.
Unfortunately in nowadays world there is a lot of monkey business going on and people need to be careful especially when buying used straight truck.
Ask For Paper Truck Warranty
It is always important to ask is there any chance they can provide you with some warranty. It is hardly to expect that it is going to be a full warranty like we get when we buy a brand new truck but still even limited warranty can save you a lot of money if something goes wrong and unexpected.
Also this is a good sign that the straight truck you wish to buy is a good one. If the seller believes in it and is willing to give you a warranty that is usually a good sign. Also be patient enough to read all those small letters at the end of warranty papers just to be sure that there is no misunderstanding.