Hello Dwight,
In Jan Still's Imperial Lugers book, on frontipiece page xxvii, there is a nice color photo of an Erfurt rig, and the wooden stock has the same, large Erfurt proof/stamp as the one that is shown on the auction...so maybe this one is the real-deal...(or maybe someone got a hold of a good stamp...).
Best Regards,
Pete... <img border="0" alt="[typing]" title="" src="graemlins/yltype.gif" />