For now all I need is a picture of one as it might have looked when it was new. The hole near the name plate was probably home to a Bramah Lock. I have seen other Mordan Product and all seem to have Bramah locks fitted. I believe this unit was probably opened many many years ago and it was dumped in the garden. I think the mechanism might have been removed and only the rust I holding the Lid/door shut.
There seems to be a lot of information available about Mordan Products, but no mention of Safes or Strongboxes, so I think these were made by someone else and badged for Mordan.