Just got this reply from Woessner after I asked for retailer address and price for their cylinder kits for KR1-S (C2)??.
unfortunatly we do not have a piston for your motorbike in our range of goods. We can offer you to produce you a piston as a custom made piece after a sample. The price would be 200€net per piston including rings, clips and pins. We always require advanced payment for custom made pistons.
Delivery time is around 4-6 weeks after receiving the payment.