The Rolex fluted bezel can be a mark of difference. Originally, the fluting on the Oyster bezel had a functional intent: it served to screw the bezel on to the case assisting to ensure the waterproofness in the check out. 36mm: This sizing is considered the vintage Rolex Datejust sizing, https://shaneqwbeg.ssnblog.com/29924820/the-smart-trick-of-presidential-rolex-that-nobody-is-discussing