The Uncanny X-Men #142. This issue is the Death of alternate future Wolverine, Storm and Colossus.

The front page has a piece missing at the bottom. Bottom left and right corner has some creases and there are some small tears (intact) on 4 or 5 pages that may be from printing.

This is a super key books from the 80's X-Men

Uncanny X-Men 142 - Days of Future Past