Proper bracelet for U serial (1997) Explorer ref. 14270?

[Chargers41]

Hello! This is my first post here...hopefully I'm doing this right!

I have a U serial (1997) Explorer ref. 14270 and was curious if the correct bracelet is currently on it. The bracelet clasp has the numbers 78790 and U4 on it. The end links have the number 558B on them. The bracelet is a OP bracelet with the foldover safety clasp. My watchmaker seems to think this is the wrong bracelet...that it should have a regular OP bracelet without the foldover safety clasp. I think he may be wrong and that would only be the case for earlier 14270 pieces. However, time to ask the experts...thanks, all!

P.s. Apologies if this has already been covered. Just want to be 100% sure in my case!