It sure looks messy. The boards are fixed into place with screws, and for these I drilled new holes directly through the bottom. The SVI case is well elevated so it does not matter much if the screws stick out slightly. The board inside is slightly raised with plastic pieces, as the existing screw holders might otherwise get in the way. Besides, there's a metallic nut in each of the holders, and it would be a pity if these created some unexpected contacts with the board circuits... So I also put some cardboard between the case and the board.
To get all the connectors visible from the backside, some more cutting would be required, but here at least the VGA and the SD card are useable. Also, If I want to use a better PS/2 Keyboard, it's within reach.
Here's some of the details:
1. The joystick connector. This fits nicely into the existing opening, and screws hold it in place. The board end is shared with the keyboard connector. I made that part to be two separate chunks, so that the joystick wiring does not hang around uncomfortably when separating the keyboard part from the case.
2. The RGB connector. It's a bit pointless to use the ZXevo with a stupid VGA monitor, so RGB is preferable. I had to carve the SVI "TV" opening a bit to make the DIN fit. Now it fits so snugly it does not even need screws really. The SD card can be seen to the right, sticking out from the opening.
Only the basic keys are connected here, as connecting all the cursor keys and function keys and such would require a bit different kind of thinking. There's a possibility of using some of the keys for the Evo jumpers (such as the reset above), as they do not interfere with the keyboard logic, but dismantling the keyboard block gets a bit tiresome after a few times so I did not take this route.