I'm just going to interject another opinion here , Syl .
I've found , during over 4 decades of collecting , researching , selling and buying art & antiques , that facts are easier to obtain than truths ( in regards to actual objects ).
Historical records can be in error , or transcribed in error : old documents/information can be authentic , as to age , but can be fakes produced during the era .
Often I've found a great variety between the opinions of professional dealers/appraisers/experts and those of a collector , an amatuer or a connesseur .
I don't know how many times I've been wrong about my own assumptions about a piece .
The same applies to the above list .
My experience is that research , research & more research (including the opinions of others) has been the most fruitful way to get to the bottom of 'the truth' about an item (sometimes the 'truth' can't be exactly found , though ...) .
That's my $0.02 worth .