Under the Equipment, Part II chapter of the Fallout 2d20 core rules, under the Armor Upgrades section, Lead Lined shows a requirement of Armorer 4, Science! 1.
In the Survival chapter under the Crafting - Armor Workbench section, it shows a requirement of Armorer 2, Science! 1. Huge difference, level-wise between the two. Would like to know which is correct.