Serious dealers, looking to sell the type gun you are looking for often expect a higher level of evaluation of their guns. But the one tool you really need, looking for a 2" gun is going to be barrel wall thickness measuring of some type. They, 2" guns barrels all started out thin, and you must find a gun with more than minimum barrels wall thickness to still be in proof. Not that dealers pay that much attention to "proof" in the US. High dollar guns deserve a higher level of evaluation and guns made with thin barrels when new do as well.