Eras and magic items / spells...

[Taqwus]

Hmmmmm. Might be the caffeine, but my brain is telling me that it's a little weird that any E1 mage can be forging Black Steel Plate (and any E2 mage, Black Steel Full Plate) without research even in the early era when equipment is generally archaic and even Ulm uses scale mails and iron caps.

Is there a way for items and spells to be restricted through the ages? Might make sense if these were Ulm-only (or required higher Construction research for other nations) in EA.