German WWII Tropical M41 Field Cap

German WWII M41 Tropical field cap.  This ones nice, but was modified by the soldier during the war.  Olive twill cotton material, has the DAK style Eagle and cockade sewn to the front.  Has both sets of vents, light surface rust, but light to the vents.  Liner is what was modified.  The cap looks and appears unissued, and may be, but the liner sides were removed at one point.  This was sometimes done during the war as this has been seen several times on original caps.  The top liner is there and nicely maker marked and stamped.  Small size 53.  Has the full sweatband in tan cotton.  My understanding was the liner sides were removed as it made the cap cooler to wear.  Otherwise its in unissued condition.  Cap is dated 43.