ERMA EP 22

This weekend at the gun show here in Albuquerque I came across a 22 pistol that had the same characteristics as the Luger. The gentlemen that had it said it was an ERMA EP22 and was made in Germany. It was in great shape and came with 2 mags and holster. One of the markings on it was a sheild with the number 68 in it. I can not recall the other markings next to this one. Can any of you gentlemen give me any information about this pistol or lead me in the right direction as to where I can learn more about it. I appreciate any input you can give me. Thanks.

Sid.