Here they are:
So I looked for a unit in the western part, and found some assigned to the Comes Africae, such as the Equites primo sagittarii (or first (unit) of horse archers), and their shield is this one:
The first shield copy comes from this document, the Bodleian manuscript, it is the second from the left in the second row:
Some more pictures of the minis. The shield identified above is to be seen on the first photo - I found it difficult to paint regular circles on so small a shield :) You may also notice that I have tried to paint better horses than usual, please tell me what you think of them.
Here you can see them scouting in front of the cavalry line:
Hope you like them :)