Many makers have sn data on line.
Branquart guns are high-end Belgian 'best-quality' guns and need to be individually appraised.
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.
Many makers have sn data on their web sites.
No, and car makers are not responsible for drunk drivers.
Try e-gunparts.com, gun shows, gun shops, custom stock makers.
Go out and find a "catalogue of Firearms" in a book store, you will find the answer there. <><><> There are several THOUSAND gun makers.
One can find plenty of information about gun shows on websites such as "Showmasters", "Cross Roads Gun Shows", "Gun Show Trader" or "East Man Gun Show".
Some makers offer historical letters. No, there is no registry that you can access.
Library, gun shop, gun shows, the internet
go to google and type in chigago and firearms manfacture,,i believe it will be a good start