This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
鉂 combines 金 (metal) with 史, but the exact historical development and original meaning are uncertain.
The left side is metal 金 and the right side is 史, but the overall meaning is unclear. It may be a metal object related to history or records, but this is speculative.
For シ, imagine a sheet of metal with the character 史 stamped on it: sheet -> シ, and the metal 金 side reinforces the material.