The Klingon SD7 was converted from a D7 battlecruiser by adding a unusually short boom section. In SFB, it is (R3.A22), found as a "hybrid" SSD/ship card in
Captain's Log #37. For Federation Commander, it is a "hybrid" ship card found in the same issue. (A color version can be found in the e-version of the SSDs for Captain's Log #37 on
Warehouse 23,
DriveThru RPG, and
Wargame Vault. The full version of Captain's Log #37 as an ebook also contains the color hybrid card.)