IWC Mark11 birthday present does not look correct

Hello to everyone. I have just joined today and must now ask for some advice if you would be so kind. For my 21st birthday some time ago, I was given a beautiful IWC watch. I loved the watch and it has been on my wrist ever since. Reading up today I am concerned that what I have been wearing is not an authentic IWC watch. On the back of the case are the numbers "6B/346" and under this is " 2205/52. It has the arrow also above the numbers. The dial on the front does not seem to match the '52 date though. The dial is the "rare c dial" which was mentioned in an article linked to this site. This dial is post 1963 so can't be right, can it? Do you think this means that the watch is not genuine? I feel very miserable about this. I know photographs always help and will take some, but just had to ask for an opinion anyway.
Thank you so much for any help or advice.

Without photos there is no way to identify what it is you have - however, a replaced dial or incorrect crown would not make the watch "a fake"!

Many of these Mark XIs were fitted with later replacement (also military issued) dials during service. They are widely acceptable. That said, only with aid from your pictures will we be able to tell.

Another option you might have is to send it in to IWC for them to issue you an extract from the archives, certifying the authenticity of the watch.

With out pictures it's hard for me to give an answer.

I'm looking forward to seeing them.