Stewhunt38

I'm new to this but would kindly appreciate some help in identifying a men's hamilton watch. It was my father's and he wore it as long as I can remember. It is an automatic circa early 60's and has a stainless screw on back and the case is gold. I guess I can't get a model # without removing the back which I'm not sure about doing. The only numbers I can see on the back of the watch are 64005-4. I would be grateful if anyone could assist me. Thanks Stu