What should i do? (Seiko 6105-8119)

I was gifted this by my father in law Seiko 6105-8119 april 1974 3 notch crown unmolested never serviced keeps time perfect crown locks bezel is a little loose and tight depending where you turn it outside that and cosmetics everything is good. Im in south jersey and need to know where to get the best crystal replacement and who to service it. I reached out to seiko they won't work on 6105 apparently. Also what is something like this worth.