Plate 12, A relief, Looking at the position of the guide dot UR, in Neinken it looks like it could be 2L, 8R or 9R.
Only one of them has an image on Doporto's site, 8R, and I think it's a possible fit, except it does not have the scratches on the right side (also not found in Neinken), but it is a possible match for the xtra ink in Ornament C.
Was hoping y'all could take a look....this one is pretty cool for me, because now I have all examples/plates for the Type II stamp: 1E, 1L (I scored a 4R1L earlier this year), 2, 3, 4 (bad copy, but it's still Plate 4), 11 and now 12.

Don't know if this link will work, but it's to my Google Photos. When I previewed, I tried to open the link to the icon with a right click, and it worked. It's a 3600dpi scan. Not a clean stamp.
Thanks in advance for your help. Always great to have you guys out there as a resource, and you are truly appreciated!!!
Ray