Advice on an inherited watch

I have just inherited a watch from my father in law, I'm an Omega guy so have no knowledge of Zenith other than I do love this watch.

I think its a Zenith – Automatic cal. 2542 PC but could be very wrong,

I plan to get it fully serviced but the strap is around an inch too short for my wrist and after numerous searches i cant really find either a strap or links that give me proper measurements.

If someone could confirm the model that would be fantastic and any pointers to strap…

Advice on an inherited watch