who is the manufacturer of this floor? thanks

These were unfinished 5" x 3/4" walnut floors that were nailed down and finished in place. You should be able to find this material through a local hardwood installer, or a flooring material distributor.

Were they glued and nailed or just nailed?

Satin/Matte is the most popular finish for Black Walnut.

Are Black Walnut and American Walnut the same? And has anyone had fading issues with either and if so what was the floor finish and what were the circumstances?

No black walnut, and american walnut are not the same. But they are cousins. All walnut will fade. Walnut and teak are two woods which get lighter with age. Most other woods will get darker with age. It is more apparent if the wood is exposed to ultra violet light.

Any precautions to take? We have mostly Eastern daylight exposure and will be using prefinished solid Mirage Knotty Walnut Savanna. Maybe the stain and Mirage's UV protectant will help delay or reduce fading some? I've heard widely varying reports of either lots or hardly any fading which seems to be affected by circumstances, and mostly reported by those that have unstained natural walnut, any thoughts?

I noticed fading in direct sunlight on my own finished in place walnut floors. The UV coating should definitely help with this. Best, Kelly

@soledad builders - Thanks Kelly, were your floors natural or a darker stained walnut, is fading so noticeable you're thinking of refinishing, and how long were floors in place when you noticed fading? Seems the UV intensity and direction of light matters too. Have your floors stayed darker under rugs as well? The UV protectant in the flooring finish along with the LowE glass will help some but I've heard all protectants eventually become less effective. Sorry for all the questions but our flooring is ordered now and we're a bit nervous about the fading possibility as well as having a softer wood. Hopefully it'll be gorgeous enough to overlook these little flaws! ;) any other tips and info is appreciated, thanks!