Thanks for all the interest and input! It turns out that Profili has the ability to generate a NACA airfoil just by inputting its numerical designation. The NACA 23012 tip airfoil was already in Profili's library, and I was able to quickly generate the NACA 23018 root airfoil using this handy feature.
I'm still doing a lot of reading to bone up on foam wing-building techniques, and have yet to decide if I'll cut a foam core with a hot wire, or use Depron and build up a wing like eflightray
did for his magnificent Sunderland. I might even try an outer wing panel using each technique to get a better idea of their relative strengths and weights. I'm leaning toward a fiber glassed skin for hangar-rash resistance, but this may be a luxury the weight budget won't be able to afford. The fuselage will be pink (or blue) rigid foam insulation, either carved and sanded or hot wired, with a skin of 3/4 oz glass.
As for markings it's still early days, but it will definitely be a Bomber Command scheme, no doubt from an RCAF squadron in No. 6 Group, and possibly Lancaster Mk X KB726, code letters VR-A, in which P/O Andrew Mynarski won the Victoria Cross.
Ah, it's good to be back...