for $4200 and it said "New, never used" and you got it and found out it was a UN date code 1999? (I missed three sales waiting for questions to be answered so I jumped on this one....)
It's in pristine condition and there are no scratches on it anywhere but,,, IMO you really shouldn't try to pass it off as "new" when in reality it's 15 years old. I like the lens and I'm not sure it's a big deal I just feel like I paid a little more to get a new lens and ended up with an old one.
How should I handle this??
If the build date is important to you, why didn't you ask for the code before you bought the lens?