Mike,
Your grips could be the coarse checkered brown HK grips...not Ritzmann type with their fine checkering and other molded marks on the inside panels.
John D. had posted these photos of real HK brown coarse grips from his 1938 HK luger a while ago on the Luger Forum. Here are his photos to compare with your pair of grips. You might look for his discussion thread on page 2 in the HK luger section titled "1938 Krieghoff " to read his tips for spotting real from fake grips as well :
