Dad gave this to me a while back. It is an automatic.

 

the case maybe a 135-003

 

movement calibre possibly a 286

 

I should have this link on speed dial.

https://omegaforums.net/threads/vintage-omega-posting-guide.383/

 

I don't think it's an automatic but since all the printing on the dial has been "cleaned" off, it's hard to tell. Read JimInOz's link.