I couldn't spot any differences between these 2 variants but I'd thought to ask here in case I missed something. What I've read is that they used the A12 to convert it to a B6. Have I missed anything?
There is a 1:72 scale Dragon #5010 Do 335 B-6 kit. I have completed it some years ago:
Painting is "probable"- two pieces of B-6 had to be produced, but it's not clear if they finally were.