Nice work. The 3 things i noticed that could be improved:

1) First of all, safes are very thick. both the door and the walls should represented as thick object

2) the object inside the safe can't be right at the front,

3)if the safe is drawn in axonometry, the door should turn according to the designed angle

I drafted a simple sketch to better explain.

Also, i'm not expert, but... In a modern safe, the hinges are inside. They are designed in a way that allows the door to open, trough an arc.

In the past, when hinges were external, hinges and door were a single piece
(To prevent thieves from stealing the whole thing and then simply unscrew the door in their hideous hideout).
I'm not expert enough to say if safes with external hinges screwed to the door ever existed or not, but if they exist, must be for small business.

Or perhaps there are safes that shows external hinges for decoration.

Keep up the good job.