Notice to Mariners

The MCA may have a historical record, but probably deep in the archives if so. M notices are generally superseded by new versions, and the redundant version cancelled, so it might well be the case that they were culled. In those days there was no MCA as such, instead shipping was controlled by the Board of Trade, so the Civil Service may be able to help. It's might even be worth a polite Freedom of Information act request?
A long shot - the National Maritime Museum may have copies?
Good luck.