It has been done. I've tinked a new housing for the LCD module. For this it was necessary to create a new circuit board, because the old board was to large to fit in the new housing. Now the whole unit consists of three parts. There is the controller board, which contains the electronic components, the display itself and at last the keys with the LEDs on another board. All components are connected to the mainboard with cabels and connectors. The circuit itself doesn't change a lot and is still based on the lowkal-project. Indeed I've omitted the analog switch 4066, who has controlled the LEDs till now. The LEDs are now connected directly to the outputs of theFlipFlop.
Here are some pictures:
The modified circuit plan, which is still to create :-), could be accessed on this page in near future.