Yes I've found it's very frustrating looking for "genuinely zero lead" brass and bronze. Almost all scrap has lead in it to some degree, and even new metal often has a trace.
Neat, this dovetails with another interest of mine, pottery. NaF is "sodium feldspar" and Ca-Si compounds are "wollastonite" among others. Both useful as fluxes in metal casting, in addition to their pottery uses.
