Are you asking how I do crafting rules, in general?If you did have those numbers, what would you do with them? How would your expert smith deploy their talents that would require a die roll on your part to adjudicate?
At the end of an appropriate time period, the character spends the reagents and makes a check. To make a basic sword requires DC 20. To make something that looks nice, and is suitable for enchanting, you need a 30. Failure on the check ruins half of the reagents.
That's what I came up with, based on what's in the book. It's what makes sense to me, given all of the contradictory and missing rules. The NPC's check bonus (and whether or not they have Reliable Talent) is important to the players, because it determines whether or not a given NPC can perform a particular task, and their relative chance of success. The players have the right to know whether any trained NPC can do something, whether they need to track down the world expert, or whether they can try it themselves. These are all things that they players would know, if 5E wasn't written with a giant blind spot in this area.