John,
I have had the opposite experience - fewer "broken" than intact.
I just had a quick look at pictures of my 12 or so Erfurt lugers.
None of the ones before 1914 had a broken die. Some in 1917 and 1918 did, but not all- perhaps not even half.
The 1917 Erfurt in this recent thread is an example:
http://forum.lugerforum.com/showthre...ghlight=erfurt
When I get a chance I'll take down the date and serial numbers of all and see how they shake out.
Perhaps others could do the same?
The thread referenced above started down this track, but no summary was ever tabulated.
I do not assume that there was only "one" Erfurt toggle stamp over the years, but I would expect several (at least more than one)l were in use at any given time. JMHO