Unfortunately i don't have any.
The only thing i have it's a rendering from Rise of Flight wich shows a late production batch cockpit. As you may see the blip switch it's on the top of the control column.

The Osprey Publishing book DH2 vs Alb D.I/D.II has a very nice rendering of what i believe to be the right layout to Azlewoods cockpit crate, being this one a early production batch aircraft (second) wich went from 7842 to 7941 serials. You may also have a look at page 29 of WD 48 if available, as it's the same layout wich goes like:

Then Osprey continues:
" Pilot engine management included... an on/off ยด'blip switch' on the top of the control column. There was no throttle - the Gnome Monosoupape was either off or running at full power - so the blip switch supplied a means of pilot engine control by 'blipping' or momentarily cutting off the magnetos that supplied current to the spar plugs."
Another thing

... that wood bracket in front of the cockpit...hmmm. I guess that this is the right clamp that Cpt. Hawker made:

It's also depicted in a pic in WD page 28.
Don't know how importatnt this is to you, i'm just giving you what i have and no matter what you decide do to i know that you're going to build a very nice model, one for us to rejoice.
Cheers
P.S. : outstanding work with the engine Prez, very very good.