So, I used to own a Filco with a Ninja case swap and two Ducky keyboards. Never compared them side-by-side but neither had any gloss to the case. I would venture to say their matte finishes were similar enough for me not to remember a difference. The only keyboard I can think of with a glossy black finish is the latest edition(s) of Das Keyboard.
I'm sure there is someone here with both keyboards in hand who can do a side-by-side.