Christian, It appears you have all of the possible feldgrau patterns of the regiment's enlisted man's shoulder straps. The ones that have or have had "tongues" (Laschen) on the reverse are the M1907 pattern. They should be approximately 5,5cm wide. The narrower M1915 pattern examples are approximately 4,5cm wide. I can't tell from your photo if the pair on the bottom right have dirty white piping or are just unpiped. If they have no piping, then they are the third pattern, the so-called "simplified" pattern which was authorized in January of 1915. This pattern was made in feldgrau wool, a lighter gray overcoat wool material and occasionally out of other feldgrau materials (ribbed wool, cotton canvas, etc.). These were superceded by the M1915s by regulation on September 21, 1915, but continued to be worn until war's end. Here are two of my examples (the M15 is half of a pair). Chip