SCUBAPRO 500. Bought from the original owner who as a Master Diver was awarded this watch by the company after winning one of his free dive competitions. He wore it every day for 25+ years which explains the faded grey bezel. Excuse the date. Old Pic. - Khurram (KK)
Sorry, Paedipod (and I see that it was your neighbors, not yours), that's no MOD watch that I know of. Not sure what lurks inside, but it taint what it purports to be.