Some of the imported blade trade information can be tracked through ship manifests, aboard inbound ships. London port records go way back. Unfortunately, they don't detail the receiving merchants as much the simple numbers of barrels of blades, point of origin, etc.
Was it 1490 or 1590 when the English ruler was angry at floods of Flemish quality steel goods and demanding/ruling there be better English steel? I forget but used to
https://www.british-history.ac.uk/ my old shelf there seems to be gone.