Hi Chris, welcome to the Luger Forum.
Regarding the grips for your 1940 Luger, they should be checkered wooden grips. They were originally stamped with the last two digits of the serial number of your pistol. There may be some of the Forum members that have original wooden grips they might part with, but perhaps not properly stamped.
If you want to settle for nice reproduction grips get in touch with Hugh Clark at hhclark@academicplanet.com
Good Luck!!