The Commodore keyboards have a 1.25 wide Control and Caps Lock keys. On this keyboard, those keys are 1 and 1.5 wide, respectively. Thus, the keyboards not the same inside. Still, there are lots of similarities. The space bar looks the same.
Amstrad boards use an interesting spring loaded design, I like to calll them non buckling spring switches. The spring is attached to a nob on the inside of the keycap. I sent my board to Haata a while back, im sure he has pictures of the internals on his site, you can pm and ask him.