Ehrfurt Lugers

I now recall that no examples of Erfurt marked Lugers had turned up with the ground receivers and restamped 1920 dates. On another tangent, it has seemed to me over the years that Erfurts in general and post WWI retained (ie with various Weimar and Nazi era mods and proofs) in particular are quite a bit less represented in the market place than their estimated production numbers should allow. It seems to me that I see 10 DWM's from WWI military origin for every Erfurt I encounter....when in fact their total production between 1911 and 1918 was much closer to the same figure (maybe DWM doubled Erfurt production). I wonder if Erfurts were singled out for scraping by the Reichwher at a much higher rate than the DWM's?