Abu,
An impossible question to answer, but how do add all that intricate detail without adding too much weight? The landing gear on the EIII is a work of art and I assume fully articulated. Beautiful models and amazing detail.
I'm currently building a BUSA 1/6 scale Nieuport 28C. Nowhere near the detail of yours, but there is a lot packed into that small airframe. Group build photos here. It will have a Saito 50 4-stroke. Hope to have it flight tested in the next month or so.
http://www.rcgroups.com/forums/showthread.php?t=2267961
I have the BUSA Eindecker EIII 90 (not scale at all, really) 80" span with a Saito 91 4-stroke and a Hangar 9 Fokker DVII with OS 60 2-stroke. Both fly very well but ground handling can be a challenge as we all know.
Jaybird