unfortunately the response, i have received was not very helpful.
So after i did some research, i think, i will mod my Keyrah a little bit.
If i understand this plan correctly:
I only need to switch the Keyrah to C64 (8Bit) mode, cut the original controlport traces on the Keyrah and manually wire the controlport cables (JoyA 0-3 / JoyB 0-3 and BtnA / BtnB / GND) to the relevant solder points at the keyboard connector, as given in the plan and it should work !
Here is a quote from the Keyrah description:
For 8-bit keyboards, the switch chooses between two key mappings: „down“ for emulators like Vice (C64) and Yape (plus/4, C16, C116), and the „middle“ position for everyday use. The emulator mapping is as easy as it can get: Every keypress will cause the exact thing that you'd expect the original machine to do when you press that key. For everyday use, the exact key mapping is described further down.
from the website here:
And since we know, that the keyboard is working, this mod should get the Joysticks working too.
(If i don't make a thinking error, but it doesn't look like...)
I'll let you know, as soon as i've done it...
Here is the Youtube video from Paul, using the Nexys with Keyrah: