I alternatively propose this 1901 contract was a package deal that included the ‘missing' 10,000 Model. 1901 is way too early for Chile to acquire the '98 as /FONT Chile only seems to contract for the '98 in 1911 and the order is for 37,000 Model 1912's made by OWG of Austria. So a full description of a German weapon would be something like 'K.98k, made by Mauser (code byf), dated 1943, serial number 1234c' Jim.Mauser did make some rifles with 5 digit numbers. Each manufacturer started over each year. German serial numbers normally went only to 9999 before adding a letter and reverting to 1. Edit: Oops, too many 9s in my serial numbering layout. After each manufacturer hit 9999 for a particular model, they would add a serif letter to the back of the s/n, and continue through, so that 9999 would be followed by 1a, then 9999a would be followed by 1b, then 9999b would be followed by 1c, and so on. S/42 shows this particular K98 was built by Mauser Werke, while the 'G' date code shows it was manufactured in 1935 the German serial numbering system started over again at '1' for each manufacturer for each year of production, so you'll find identical serial numbers throughout each model for each year of production, and each manufacturer would have identical serial numbers.

Mauser 98 serial number locations