I have not found any information on things like hammers, forging techniques etc (apart from the mention of forging at red heat and the time of day). Smiths were not usually literate and no one really cared about their tools. In the archaeological record, craftsmen would have passed down their tools and/or took them with them so we have none. In many parts of Central Asia they did not bury the dead with goods, so we have none from their either. I will keep looking.