Seeking advice on 1958 Seamaster

Try this search to find an AWCI (American Watchmakers-Clockmakers Institute) professional near you specializing in vintage watches. You may also try the NAWCC (National Association of Watch & Clock Collectors) search page.

You want to ask for a "clean, oil, adjust" service of the movement. The watchmaker will clean the movement, lubricate it, and adjust the timing. It is possible that internal parts may be worn, and a good watchmaker will advise you of the options. It's hard to tell from the photograph, but a good polishing of the crystal may be all that is needed - although if the crystal is cracked or yellowed you'll need to replace it. Avoid having the case polished or buffed by machine. A gentle cleaning should suffice.

It seems that the hands and crown may have been replaced at some time during your watch's lifetime. The dial seems to be missing the minute markers which suggests that, at some point in the past, it has possibly been repainted or touched up as was commonly done. But, none of that really matters because your watch has a special status, as an heirloom. 😀 A new leather strap and you'll be good to go.

Everything looks original 😀
A US-cased version with a cal. 500 movement which was made for that market. Lovely heirloom.