At NARAM 60, I had a discussion with a scale judge regarding the correct finish for my Saturn 1B entry. My Saturn 1B had a nice glossy finish, but he pointed to a couple of my substantiating photos (the Saturn 1B on display at Kennedy Space Center, and a Saturn Instrumentation Ring located in the museum in McMinnville, Oregon - both of which had a matte finish. I responded that the hardware in those photos was ~50 years old and 'well weathered' - and that the all the photos I'd seen from original hardware from the 1960's appeared to have a gloss finish.
He didn't say as much, but I got the impression that I'd lost a few 'finish' points due to the gloss finish (another Saturn 1B entry that ultimately finished first in sport scale had what I'd call a satin finish).
So, who's correct? As noted, most the 1960/1970 vintage photos I've come across of the Mercury Redstone, the painted portions of the Gemini Titan, and both the Saturn 1B and Saturn V appear to show a gloss finish - but losing scale points with a gloss finish - even though it's correct - would be something of a pyric victory...