1. Granite It has ALPS White switches

2. RT6856T This is already articled in wiki. No new things

3. SK-2052U(JIS 109) with SiliconGraphics logo FCC ID is GYUR58SK.
I searched this on FCC site. But there is no info

4. 6511-BN(US WKL 101) with sgi logo According to Silicon Graphics article in jawp, sgi logo began to be used from around 1996. Thus, this one is newer than above.
Made by Darfon Electronics.
5. 6516-BN(JIS WKL 106) with sgi logo