Chuck
What an Honor that will be to Model an Airplane from your Dad's Squadron. That will be a very fulfilling build to say the least.

I sure like what you have done with the control cables. I had the same Idea in mind. With all of the research I have done into the various models of the DH4 I have yet to come across good drawings of the cable routing. Your pictures will help a great deal. Are you using Proctor Pulley's? If not what did you use?
I was actually disappointed not to find a whole lot of reference on the early DH4 as Kitted. I bought the kit taking for granted that there were more of this kind out there than there really was. I have been making plans for the alterations but I still like the version as kitted and still might just do it that way.
What do you think of the engine you selected? I am new to gas engines and have not heard that much about RCFG. I had planned on using the same engine Dick Pettit used in his DH4 mail plane, The YD Aero 56cc. Not a lot of room up front for the more popular choices.
On your finish, Is this Painted or the colors of covering used. I am planing on using Solortex Myself.

Great work.
Trev.