I have noticed, looking at other peoples watches that their steel bracelets have a number on them, by the watch back. On checking mine, it doesn't, though there is a number on the clasp. Is this correct ?

I bought the watch through Watchfinders, with cards and boxes in as new condition, though it is a 2013 model.

 

I guess you are referring to the number on the end links? In my experience there should be a number. My 105 003 65 Speedmaster has a 1035 bracelet with the number 6 stamped on the end links and my modern Speedmaster 60th also has the number 6 although etched. I also have a spare 1171 bracelet with 633 stamped end links.
You really need a reply from someone with your actual model to be sure.