I found a (most likely) soundchaser-clone.
It was made by Jen elettronica in 1982/83 and uses the Mountain Computer Music System. Currently only the interface is in my posession but i have aquired the Keyboards itself (in transit) and maybe even the software (part of a 100 disk package from the same seller).
This is all very interesting as i did not know that there were clones of the soundchaser.
This interface has the same layout and most likely the same piout as the SC-interface.
As soon as i have the Keyboard ans Software, i will post updates here.
I intend to supply pictures and diskimages to the A2DP as soon as i have everything here.