It might be that I do not understand what precisely is meant here but I guess some explanation about the numbers of Mk 11 watches might be useful.
First of all, the cases of a military Mk 11 ( there are also civlian ones) has no case serial number but only a military inscription on the outside of the case back. The number 181/52 means that this is watch nr. 181 issued in 1952 by RAF. The movement number is from 1950 and was allocated to a cal 89 INCA S.C. This exactly the movement of a Mk 11. The fact that the movement was made in 1950 and the watch issued in 1952 is not alarming but normal. I have not seen the watch but its numbering looks ok to me for being a genuine Mk 11 from 1952. And I thought that was the question asked.
Kind regards,
Adrian
(alwaysiwc).