Hello Stuart,
The resolution of your photos do not show a lot of detail, but here are my thoughts :
1. Erfurt grips would usually have the Crown/gothic letter inspector's stamp on the inside of each grip panel. They are small, and are easy to miss. My 1913/1920 double date Erfurt also has the last 2 numbers of the gun's serial number stamped on the inside of the wooden grip panels as well.
2. The wear of a luger should match, somewhat, the wear of the grips. That is, a mint luger should not have worn grips and vice versa...
Regards,
Pete... <img src="graemlins/yltype.gif" border="0" alt="[typing]" />