Geno...email to me your post address and I will provide copies of my published articles regarding serial numbers for you. (this material is copyrighted) As Clair has noted above, some of the record books have been found in Suhl archives but unfortunatly all(?) of the early Sauer record books are missing. (Or perhaps not yet found) As I understand it, the Sauer books that were found date from the 1920s up until the 1940s or so.

Jeff Stephens