Replica. The seller is trying to obscure it by not showing the engravings between the lugs nor the bracelet clasp engraving. Look at the case back inside engraving. There's no way that kind of came from Rolex, it's doubtful that a 50-year-old watch would look so pristine with not a single mark on the case or bracelet or clasp. The movement engravings are not accurate to how the genuine would look. A quick search of Google brings up dozens of different listings like the one below, none of which match what the real movement would look like.
cjx.cdsefa.top/ProductDetail.aspx?iid=62881656&pr=91.88