Valian Year 1497

[Aiwendil]

I might be wrong, but do folks disagree (or agree) that this means seven years into 'year' 1497 (using 1 Valian Year = 9.582 Sun Years here, not 144).

That's how I interpret it. Well, to be completely precise, not necessarily seven (shorter) years into Valian year 1497, but seven years after Morgoth's first assault. We don't know exactly when that assault occurred - if, for instance, it happened 1 year into Valian year 1497, then that would place Feanor's arrival 8 years in.

On the face of it, this appears to me to agree perfectly well with the Annals of Aman entry. Note that the AAm entry gives no indication of when, within 1497, the events it relates occurred. It could have been late in 1497 (already close to seven years after Morgoth's first assault) that "The Noldor came at last far into the North of Arda, and they saw the first teeth of the ice that floated in the sea, and knew that they were drawing nigh to the Helkaraxë".