My grandfather was given a seamaster for his retirement from Boldt castle in the early sixties. I can not find a picture of any with the same type face, and would like to identify.
I've seen "shell" dials like that before. Totally legit. Early 1960's sounds right. In order to properly identify the model, you'll need to take it to a watchmaker with the proper tools to remove the crystal and stem. The movement comes out the front of the watch and the model information will all be inside. Hope this helps, gatorcpa
This sunray type is one of several dial variants used in the same case(s) and it's the case that will tell you what you have. The watch movement will be a 552 or a 550. Do lots of image searches for Seamaster 552 and you should be able to narrow down the case reference but you'll only be sure when or if you take it to a watchmaker for servicing, which it will undoubtedly need. You won't be able to take the back off yourself as this is a one-piece case and the movement comes out through the top, which it's best not to attempt with no experience. The watch seems to have had a hard life, with water ingress around the 3, a poor quality replacement crown and the lugs bent out by the strap, or is that an effect of the photo angle? It's not hugely valuable in that condition but it does have a value, and the dial variant is nice and quite scarce. Worth cleaning and servicing for family reasons.