I have to admit, I thought it looked like a RN4081 from the initial picture you posted (I thought the VK was a 2-piece model?), but I do not have any experience of one of these myself toi give you absolute confirmation.
If I were you though, I'd buy a few carts for the RN4081 to see if they fit (I think they almost definitely will)
If I were you though, I'd buy a few carts for the RN4081 to see if they fit (I think they almost definitely will)