I got them at my dealer.
(Actually they installed them prior to me taking delivery, and since they were an option, I just presume they stock them. Maybe they had to order them?)
Edit: Sorry, I spoke too soon. I see what you mean. I can't find them for that model. I have an RCR1860 and they do list them for that model at German-bliss.com but not for the 1260
You might have to "retro-fit" a different models chain guard to fit yours.....