Unless he had the receipt , there are no charts and even asking Borgani generally returns an estimated date. I have actually owned a few and never noticed anything strange.
I tend to agree with this. Borgani and many Italian mfrs didn't use sequential serial, um...sequences. So their numbers do not represent a 'straight chronological line'.
The only reliable way to ascertain the date of an old Borgani is:
a) a seller who can confirm when it was purchased new
b) contacting Borgani and hoping that someone there will bother replying and give you an answer.
c) finding someone who can honestly say "I had the exact same (or really similar) model, and I bought in new in 19XX"
Having refurbished a good 15-20 old Borgs, at least 6 of 'em being Tenors and some with attributes such as this one, I can tell you.....yes, some can be 'flexy' intonationally....but not anywhere near nightmarishly so. The only time that has happened in my experience is when the player really has undeveloped or poorly developed embouchure, or when the mouthpiece match is just way off.
But nothing a player who is familiar with vintage horns , or one who is a pretty solid intermediate player on a modern horn, cannot deal with. And the payoff is the tonal quality.
(note: I am NOT saying reports of intonation issues are 'lies'...I am simply saying in my experience (and I have more firsthand than most people...although perhaps not quite as much as Milandro)....it's not quite so).
In this instance, seller asking $600....no significant damage, and seller confirming the horn does play up and down at least half-decently ?
Pretty good buy, IMHO.