As far as I have known, the only accepted white frogs were made by Fischer, Berlin. I believe they were primarily used by Polizei units on parade duty & had limited use by the Liebstandarte on a diplomatic trip to Japan. The original frog posted in this thread looks to be a complete reproduction IMHO.
This one was purchased from the late Chip Gambino. Legit examples are not cheap but do create a striking appearance, don't they?