Thanks for the replies, gents.
Basic 5-color camouflage now done, with masks cut from a multi-view drawing of the typical Kellner pattern blown up to model size. 'Dope' colors on the fuselage are by-eye Tamiya mixes, based largely on color photos of NASM's 'Smith IV.' Darker colors on metal-panel areas represent the oil-based ripolin paints used on these parts on the real a/c; these tones were close but not exact matches to the fabric-area dope colors, which contained a significant quantity of aluminum flake/powder to resist sunlight damage.
I actually added a portion of aluminum paint to my camouflage color mixes, to try to match the slight-but-noticeable 'pearlescent' quality of the dope on the 'real things'; but it was virtually invisible once the paint was applied to the model. On a wild hunch, I then added a bit of the same aluminum to a bit of Future clear---maybe (1) part paint to (20) of Future (I didn't measure)---and experimentally brushed it onto the tail section. The results were just what I wanted---an ever-so-slight 'gleam' with no actual aluminum visible unless you look microscopically close. I then brushed it on overall to fabric-area upper surfaces, and was exceptionally pleased with the result. Not highly visible in the photos, but really makes a difference in person.
Decals the next challenge. My experience with Hobbycraft decals suggest a coating with Micro-Decal film migh be in order for those from the kit sheet...mainly roundels...that I intend to use. Inkjet-printed my own decals for personal markings and such for the scheme I've chosen---here's hoping the red borders on the numbers don't bleed or blush.