Refined Dustin Silver Knight Armor is crafted with Blacksmithing in Mabinogi (armor). This page lists everything needed to make it, checked against the game as it exists today. The interactive planner lives in the Blacksmith Companion.
How to get the manual
The manual is rank 1 and survives 30 uses; every crafting attempt spends one use.
(Refined Heavy Armor) Blacksmith Manual Fragment: boss drops in Rundal/Ciar/Alby Advanced Hardmode and Rabbie Phantasm dungeons.
Materials
Expect about 4 attempts per finished item (28% average progress per attempt). Per-attempt materials are consumed on every attempt; finishing materials once per item.
Each attempt uses
5× Phantasmal Ingot — crafted product, no gather/drop method exists
2× Polished Plate — crafted product, no gather/drop method exists
10× Finest Leather Strap — weaving rank 3-1 on a spinning wheel