That's a beauty, Hawker and really speaks of your expertise, Sir.
I've seen larger from 1/2" plate w/fire brick liner destroyed in 3 weeks and a 'Safety-Kleen' 30 g. solvent bbl go 23 yrs w/a Sotz kit and thermotsat.
It certainly appears ~ this isn't your first 'rodeo', ha.
A few here have a thermostat to prevent 'run-away'. Something to consider.
Is that a secondary air intake below the smoke shelf? Looks to be 2" on the back panel of the firebox.
Do you plan on woven sealer on the doors? Helps with complete shut-down, if ever needed.
Is the door air control free spinning or on threads with friction and an internal heat shield, to avoid it having a mind of it's own, ha?
Will you be using exhaust manifold paint and the first slow burn outdoors?
Sure appears durable enough for you grand kids.
I'll stop ~ Stay safe...
Tom