I've gotten so much from reading these groups over the years I thought it was time to post something that might be of use to someone else. I've enjoyed your building techniques for years now so its gratifying if you can get anything from my experience. One thought struck me as I did it too. It really makes these projects significantly longer if you are documenting it. Made me doubly appreciate the time put into helping others from experts like Tritle, Hammered, Rake, Maltone, and on and on.
My thoughts on your small scale stuff:
I'm guessing that every tenth of a gram is significant on a project so small. There's a Smooth-on distributor in Dallas that I stopped at once and I looked at that feather-lite resin. It might be much lighter than a regular resin, but my impression was that it was still much heavier than the two part foam they sell. If you are making very small parts, I don't think you would save anything by using the slosh method to make a hollow shell with it. I've never tried to make anything smaller than a 1/18th scale figure, but I was happy with the results I got with the foam and techniques above. Managed to make one that weighed just a gram.
Seems that at 1/24th to 1/32 scale, you are approaching sizes that are commonly modeled in plastic. I wonder if you could find a nice plastic kit on ebay with a pilot figure. Then you could just make a mold of that. I've heard tell of old Airfix kits (spitfire and me109?) that were 1/24th scale.
a quick search on ebay yeilded these.
May not be exactly what your looking for but it might be a place to start.
All the best,