Keeping unskilled engravers away from a job site

I'm about to start digging out a flashy tomb for my fort's baron, and I want to engrave it wall-to-wall. I'd like to let only my best engraver do the work. I could lock him in easily enough, but I don't want to risk him starving if I forget about him and he runs out of food. Is there some way to keep the other engravers out while still allowing the good one to leave when he needs to?

Edit: screenshot attached.

Further plans involve a gold sarcophagus, gold and silver statues, and maybe some stupid magma tricks.

Edit: another screenshot

The tomb has been completed, and here's the payoff:

Simple Solution:

Use Dwarf Therapist to disable the engraving labor on everyone but your most skilled stonemason. Re-enable once everything is engraved. You can let everyone do the smoothing (there's no quality value on a smoothing job), and disable them when you're ready to engrave the whole thing.

Complex Solution:

Use Burrows to restrict your non-target Engravers into other parts of your fortress. Your master engraver will be the only dwarf able to reach the area, so the engraving job will call him. (In Dwarf Fortress, Jobs pick dwarf!)