A vintage Rolex GMT Master from 1978

A very tasteful Rolex GMT master made from 18ct yellow gold and stainless steel. The watch has the original hands and brown “nipple” dial which have all aged beautifully. The case is in very good shape and still heavy. The case number is a 528**** indicating that the watch was manufactured at Rolex Geneva in 1978. The question is who’s 40 this year and would like a birth year watch?