Firstly, the Poker II has a steel plate already. Why change it? Secondly, the GON plate will fit, but REQUIRES pcb mount stabilisers, whereas the PokerII has plate mounted stabs, so you'd have to also buy some pcb stabs. To change the plate you have to remove the keycaps, unmount the board from the case, desolder all the LEDs (if your board has them) and all the switches, change the plate, resolder all the switches and the the LEDs. It's a lot of work.