I did a quick search for you via online retailers (I don't do gunbroker or those auction sites..personal decision) and NOTHING.
I would suggest that if you get no hits here for anyone to sell to you check with you your local gun stores that are authorized HK dealers and they can put an inquiry in with their providers to hopefully secure you one. I know they just released the FDE colored ones too. Good luck in your search! I bought mine from EuroOptics for $2500 in January before COVID and prices jumped. And I love it! Also may want to entertain picking up an extra MRS 5 slot rail if you want to use a fore grip or bipod with it.