On a side note - the front fenders on my 1968 Mustang have unpainted attach hardware (bolts). See pic below.
I had the car restored in 2005/2006.
Before I had my car restored, I was at the 'Mustang Round-Up' in Bellevue, WA to do some homework on who could do the work - and just have fun.
I was talking to one fella who had his 1967 Coupe on display. He and I were talking right when the judges came through to judge his car.
I stepped back and watched the spectacle. The 4 or 5 judges spent 20 minutes discussing what the correct color anodize was for these very bolts and the implications of such highly important features. They got to the point of not only discussing what the color was/should be but also - was it supposed to be flat? Satin? Shiny? Jeezzeee....
The rest of their judging time was equally obtuse... Blew my head right open - and I left the area wondering what I was getting into....
Witnessing that - I made a personal vow to never show my Mustang in any MCA judged show. The shop that did the restoration on my car was disappointed at that (for they would have appreciated the exposure showing my car would give them) - but - they did understand why I would not want to go through that BS.
For my car - I am on the fence with how I will 'show' my car that is coming up on delivery from SFDon... I really don't care about originality (in this trivial way) - but I do want to have fun with the car. Will see how my time with the E9 goes moving forward....
Below - For the Mustang, you can see the before (with fender removed) and after (with the silver anodized bolts shown).
The reason the Mustang has unpainted fasteners is that the hood, fenders and some other smaller body items are painted off the car and then installed. So, makes sense to not have fasteners painted.