I found that the best way for cleaning and polishing the door and the jamb threads is to use 3M EXL wheels on a die grinder. They are expensive but are cost effective in the long run and do the job fast. Norton also makes a similar wheel. That will remove the rust quickly and lightly polish the metal. More than likely the threads will be steel but the stepped body of the door and the jamb will be laminated burglar plate. The body of the safe will be made of the burglar plate as well. It is easily identified as you can see the layers of iron and chrome steel laminated in each piece. The burglar plate was advertised as burglar proof, used in safes, vaults, and in the construction of jails and prisons. The pieces are stacked to create the stepped body of the door and the jamb. The mating surfaces of the door and the jamb should clean up nicely. Here are some pictures from of one of my Mosler projects.
I just noticed the third picture shows the slot in the door where the latch fits. Yours may be different.




The one Mosler even has an indicator for door closed position.
