Complex sentence: Construction of the knife took five years and contained 32 ounces of gold including a blade cast from gold and specially heat treated, this knife was a stand-alone project, but became the first of his "Legacy Knives".
Split into simpler sentences: Construction of the knife took five years and contained 32 ounces of gold including a blade cast from gold and specially heat treated. This knife was a stand-alone project, but became the first of his "Legacy Knives".