Those using that book should be aware that while it has plenty of useful info, it also has a reputation for containing multiple errors. So best not to treat it as definitive or a slam-dunk resource - it is one data point for discovery and discussion.
Since I know I am going to be asked for examples, I will mention what I discovered when researching the M94, since I was in the market for one. Page 10 states that carbine production began at Carl Gustaf in 1896, but it is well accepted that production of the carbine in Sweden did not start until 1898. Then on page 6, we read that "Production (of
Swedish
Mausers) began in 1894 with 52 prototype carbines and continued uninterrupted at Carl Gustaf from 1898 to 1925 ... ." While the Receiver Production Table on the facing page shows M94 carbine receiver production occurring at CG beginning in 1901. That table is reproduced later in the book, where we read that "the lowest C-G manufactured m/94 carbine serial number observed by the authors was 40,070, dated 1900." And then, "Our study of Swedish carbine serial number have (sic) led us to the following tentative conclusions: ...3) A total of 115,000 m/94 series carbines were manufactured at CG. They fall into two groups of serial numbers: A) circa 10,000 to 54,000 manufactured between 1901 and 1907." This is contradicted by their own statement on p. 10 and by their stated observation of a 1900 dated m/94. This is all very muddled at best. And confusing for someone contemplating purchasing an M94 with an 1898-dated receiver. I'm quoting from the 3rd edition of the book from 2011, by the way, whereas the far superior book "Crown Jewels" was first published in 2006. The 3rd edition is labeled "revised," so there is really no excuse for ignoring the other publication to the extent that appears to be the case. I can't speak to other errors in the book, but my online research assures me they are in there.