My time frame for kit bashing the Cessna Skymaster isn't anywhere in the near future either. I have many other projects ahead of that.

Just think of me or do a build thread when you get around to doing it. I gotta see it. I will also do a thread on my bash when I get around to it.

The engine nacelles:
Maybe you could make a lite-ply pattern that would match the current rib profile? You could extend that ply out in front of the leading edge.

The sides of the box would have to be installed during wing construction because of the notches for spars. Add some lite-ply formers with stringers to round it out and give it some shape. Or balsa blocks could be glue on and sanded to round it out. Install the leading edge and then just cut it out between those 2 ribs.

Make the whole thing big enough and you could stuff the 6oz tanks IN FRONT of the spars. Or you could always make your own custom tanks out of brass and silver solder them together. That way you could get them shaped to fit exactly in between the spars and ribs.

A rough idea: