• Swap control and caps lock
• Swap “ and @

xkb is configured in /etc/X11/xkb/ the Kubuntu fix worked on first log in, but after a random period the arrow keys would stop working and it would revert to an otherwise US keymap. i'm assuming this is associated with a fight between setting the map manually using setxkbmap and using the kde config tool.

so instead i've modified the standard gb keymap to add a new variant at the end called hybrid (or US Hybrid in full). in order to get this to show up in the kde config centre, i had to copy over the new definition itself into symbols/gb and modify the following rules files in order for the config tool to pick it up: base.xml evdev.xml (and maybe base.lst and evdev.lst – not sure whether these were important, they are old versions of the same information. but just changing base.xml didn't work). these are in rules/