WW2 German Kriegsmarine Coastal Artillery Overseas Cap 56

For sale is a nice KM coastal artillery em/nco overseas cap that appears to be repaired. The back 1/3rd of the cap is a different wool & liner material machine sewn together. It was possibly done as a repair but an explaination other than that eludes me. The ink stamp survived, cap is dated 1940, size 56. The liner material in the rear appears to have less wear to it than the rest of the lining, suggesting  (again) that this was a repair done at a later date.