Go out and find a "catalogue of Firearms" in a book store, you will find the answer there. <><><> There are several THOUSAND gun makers.
No. No one can. There are a lot of custom rifle makers and major gun makers that make rifles chambered in 7x57
Proofhouse.com has sn tables for some makers. Some makers have sn info on their sites. Books.
Go there. Do an internet search for Hungarian Arms makers.
Buy Terry Wieland's book 'Spanish Best'.
That is a VERY long list. Beretta lays claim to being the oldest gun maker still in operation. Some of the others have included Mauser, Walther, Holland & Holland, and Westley Richards. Depending on which country, there are HUNDREDS that can be on the list.
No, and car makers are not responsible for drunk drivers.
Try e-gunparts.com, gun shows, gun shops, custom stock makers.
Many makers have sn data on line.
Blue Book of Gun Values is one.
Brown. British gun makers, vol. 1. Page 105 gives a list.
Some makers offer historical letters. No, there is no registry that you can access.