@borndead
Sorry for reliving this issue, but I could not reach the solution you explain.
I have the same problem, I want to connect 4 controls (2 snes and 2 nes) and the power off and reset buttons.
The truth is that I don't know how to rebuild the driver.
In this link is version 1.4 of the driver, it is easier to modify the pins, but my problem is in reinstalling the driver
https://github.com/marqs85/gamecon_gpio_rpi/tree/master/gamecon_gpio_rpi-1.4