My dad's 30-ish year old Seiko has white crud at the 12:00 marker. I think it is adhesive from an old repair (possibly a crystal repair with the dial still in the case?). Any thoughts? Would it be difficult to remove? I'd like to clean it off, but as a newbie I also want to leave well enough alone. I have cleaned the case and band ultra-sonically and have installed a new crystal, crown and cover gasket along with a new battery.
I'm tempted to put it back together as is and give it back