After a long period of development, bug-fixing and testing, The Eiffel adapter with joysticks is finally on sale at Klyde's Korner in two versions: assembled or as a kit.
The Atari Eiffel adapter with mounted joystick ports is here
The Atari Eiffel adaptor with Joystick ports in a kit is here
Attention, As I was relating it in a previous article, Not all games support Eiffel joystick emulation, it's random. You have been warned.