Brilliant work on the office, Patrick, and that engine is fantastic! I agree with the other guys regarding the decals. The Superscale sheet is well worth the money. I built this same kit in 1/48 scale and it was essentially just a scaled down version of the one you're building. I used the kit decals for Rickenbacker's personal markings and the Superscale sheet for the roundels, fin flash, stencils and every thing else. The Roden decals gave me nothing but problems, but the Superscale decals went on flawlessly. I would pass on the Roden decals, my friend.
Cheers,
Bud