My Lord Northcrest,
It was with some effort we converted the sealed chamber into your new vault but the result was a resounding success. The switch to open the concealed entrance is hidden behind the painting with the lion you specified.
As laid out in the proposal, the original monument within now holds the key to securing your most precious belongings. Rest assured this correspondence was hand-delivered and remains the sole copy.
Your faithful servant and artisan,
Theodore Eastwick, Royal Architect by Appointment