Not quite. More accurate is that it is usually difficult for experts to make a definitive assessment from photographs and a few testimonials from a source with vested interest, however disinterested that source purports to be. What is an acceptable risk of misattributing an instrument when the difference may amount to a few hundred dollars, becomes unacceptable risk when the difference rises to thousands, or tens of thousands or more. A reputation only adds to the stakes, and consequent lawsuits are not unheard of. In the case of potentially valuable instruments a close-up and personal examination is at least de rigueur if not mandatory, certainly good practice and maybe even common sense.