How old is my Trek 520?

I bought her two years ago and people ask me all the time how old she is. The person I bought her from said she was a 1990. However, a mechanic thought she was younger.

The medallion came off during a storm while I was touring. I still have it.

Obvious, there’s been work done, but is it still possible to tell? If none of these photos offer clues, what would?

Photos of her being boxed (Arizona) and unboxed (Wales) and the mechanic working on her.

I’ve done three tours of Scotland and one of England on her. She’s a tank, I don’t travel light!

Thanks!