Something interesting... On Page 37 of Uniforms and Traditions of the Luftwaffe, Vol 2, There is a discussion on various collar tabs of Admin General Officers. IAW the forestated reference, on 19Aug44 there was a Construction branch of the Administrative Service that had BLACK collar tabs with gold embroidered triangles and wreath... So why not more junior rankings within the "Construction Admin", or even Wartime Specialists(this would explain your two sets). I learn something new every time I crack this books open! Regards Paul