red sub bracelet

[Droggo]

My 3.8m red sub has a 7836 bracelet, according to this article:
https://www.watchprosite.com/?page=w...211&pi=4075146

Quote:3. Occasionally, a Red Sub will be found to have a 7836 Folded Link bracelet installed. Although it was designed primarily for the GMT and the Explorer II, the 7836 fits the Red Sub perfectly and can take 280 or 380 end pieces. The only major difference between the two models was the clasp. The 9315 had the flip lock and the divers extension and the 7836 did not have these two features.

Is this possible or did the original purchaser have it fitted, it was serviced by Rolex and they never commented only on it.
BTW it also has a MK2 white dial (NOT A SERVICE DIAL)fitted again no problem when serviced although a massive kick in the teeth for me regarding vintage originality and therefore value.