Something worth considering if planning to do a B-29 in foil. Just a suggestion but i did do it to see if it really worked or not.
1) Get the wings constructed, fill and sand the seams. You may need to add some sheet plastic shims to the side walls of the wheel wells. Academy engineered the kit in a wacky way that make proper location of the engine nacelles on the wings very vague and imprecise. Also, the back sides of the nacelles don't fair in very well with the molded aerodynamic fairing on the flap insert.
2) DONT Attach the nacelles to the wing yet.
3) Assemble the engine nacelles.
4) Measure, locate and mark the proper location of the engine nacelles on the wngs. Test fit them in place but DO NOT GLUE yet.
5) Take a large piece of Bare Metal adhesive backed foil, and apply to the wing where the nacelles go.
6) Slip the engine nacelles onto the wing leading edge, locate them precisely and glue them in place (yes, over the foil) with super glue. The thin CA is probably best.
7) Fill any remaining gaps along where the nacelle meets the wing with a 50-50 mix of thin CA and medium viscosity, gap filling CA. Allow to dry without using accelerator.

When dry, carefully twist/slide/ crack the nacelles free of the foil and the wing. Scrape the foil off the wing and sand the attached foil and excess super glue away from the engine nacelle using rigid backed sanding sticks and Flexi- files, finishing up only at the end with hand sanding (wet). Restore any missing surface detail on the nacelles (if desired) with scribing and engraving tools of your choice.
RESULT- a custom-tailored engine nacelle that can be left off until very late in construction, that will have a snug fit and require very little glue. This will allow you to foil the model without the nacelles getting in the way.
Hope this helps.
Cheers,
david