jubilee end piece 555B fake or real

[simon B]

Hi Group, I'm new to your rolex forum
I'm a watch repairer from the UK mainly dealing with Omega, Longines etc. refuse most Rolex jobs due to the spares issue.
I stupidly bought a 1603 basket case (90% Rust), I have a passion to take a pile of scrap and return it to mint using only correct parts.
My question is I have bought a jubilee from ebay which was listed as genuine rolex except the centre folding clasp ,end piece were listed as 555 which would be correct - bracelet is nice but I do suspect it is not rolex. the end pices are marked 555B, two questions - Did rolex make a 555B ? the position of the 555 is more on the "centre right" of the back not running into the ear. Both pices are stamped on the right side, is this position correct .
Thank you for your help. There's a mine field of fakes out there this guy deals mainly in rolex so hopefully he will return my cash
Simon