I scanned these some time ago. I think they’ve been hosted elsewhere by others, but they were all scanned by me originally. When I bought my MK1, it came with the German user manual; I bought the others on eBay. The German MK1 user manual is complete although not very good. English MK1 manual omits most of the sound programming sections, so you’ll have to refer to the German manual for that. The English EX20 manual isn’t particularly useful. The service manual is for the DX10 organ (the EX10R is the rack mount version of this). This shares most of the hardware with the MK1 and EX20, and also includes a drum board. I’ve seen a Wersi DX5 service manual floating around too. It’s electronically similar, but the boards are mostly different and not interchangeable with the other models. The matrix overlay diagrams are cobbled together from the German MK1 user manual.

Wersi MK1 German user manual

Wersi MK1 English user manual

Wersi EX20 English user manual

Wersi DX10 English technical manual

Wersi MK1 matrix overlays