Well! My build started today and is already looking very promising.

I really need some input though about the panel indents. I'm making a kind of Met/Yardley-Jones hybrid and the method of door/wall construction we're using is cladding ply sheets with blocks to make up the panels. For speed and ease we're thinking of routering the panel indents and finishing off with a chisel; at first we were going to leave the panels without angles (a la the Brachacki box) but the panels are going to be quite a bit deeper so will look odd without angles.

So my question is - as we've bought wood the right thickness for the generally accepted classic Yardley-Jones dims with the panels at 12" x 15" with a 3.5" horizontal style between, will it look odd and out-of-whack to router away from the edges, effectively making the panels a teeny bit (1cm) wider and taller?

I had heard that this is why the windows on the McGann box look squarer, that they had done a similar thing on there.... There are worse boxes to emulate.

it works... and i used a router on my panels. i'd definitely angle the edges its just one of those little touches that makes a build.  again the problem with the router is the rounded corners.... i didn't chisel out mine (lazy, or either just in a rush... probably a little of both) the other problem i had was that my router bit wasn't 1 inch at a 45 degree angle so the edges are angled but don't angle all the way to end.

remember that when you look at the panel head on the chamfered edges do not affect the overall width of the piece!
if you measure from the outside of each chamfer, it shouldn't change the width at all

this detailing is only really visible up close or when the light hits it just right