Doing this seemed to fix my problem. More specifically, I
- removed the anvil from my home
- researched a weapon at Danos’ scribe table
- went to Filmore and checked his anvil (everything was there, when before there wasn’t)
- placed the anvil back in the home and checked (everything was there, when before there wasn’t)
Thanks for the suggestions @Silas-Inservio-Pax!