I like your idea of everything original, but in the bolts and nuts area, I'd just go to a Bolt Supply store and get what ya want in Chrome or Stainless Steel for about 1/2 the price.
If you should happen to go to a car tire, you'd have to do the fender mod and ain't no way you will find the required carriage bolt in Honda's part.
Just a suggestion.

I live in San Marcos, Texas... no metric stainless here, bro! It's 42 miles to the nearest "nuts and bolt store" heading north all the way through downtown Austin. 32 miles to the nearest "nuts and bolt store" heading south... right through San Antonio and some of the heaviest traffic anywhere... by comparison to all the running around, the $2.19 for the mail order OEM chrome bolt holding my fender rails on doesn't seem so bad...
Perhaps I wasn't being clear, I ALREADY have what I need for mounting both fenders, including the "nut job." (which I have been called before...) I am wanting to find some way to find to find similar chrome Honda bolts to use for the upper and lower shock mounting bolts... I know they are out there... Ive seen them on similar bikes.