Here is some information on the Admiralty Police which maybe of help to you.
There is a gentleman called Mr Harry WYNNE who is has produced a pamflet on the various HM FORCES Police and if you contact him he may answer your question.
neharrypolice@yahoo.co.uk
Here are some scans of info
I cannot seem to upload my scans so if you PM your e mail address I will send them to you
I currently do not have the Insp badge but still looking.
Regards Jerry.