I had surmised that the different style of the doors, and different wood, could be explained by the original doors perhaps being damaged at some point by a break-in, and then replaced. OK. Maybe. Then I surmised that this could also explain why the whole pantry was painted, because the new doors would have stood out too much.
However, I have now disproved the latter:
So, you see, it is all rather a mystery!
Here is my guess:
The original drawings give no indication of a “silver safe”.
However, as drawn and as built are often different so the drawings confirm nothing.
It seems highly doubtful though that the original architect would have, late in the game, created a silver safe which was so at odds with the rest of the pantry.
Thus, I am going to guess that the “silver safe” was created a decade or two after the house was built. But even this does not explain the use of a different wood, a different style door, and the lack of alignment.