This is actually an interesting question that Rick and I had discussed when he was writing Legal Muscle. Unfortunately it could be a potential charge in which case the penalties may be far more severe. I have to take a look at the Federal law again, but as far as state law, it would come down to the language in the statue of that particular state, the definition of manufacture, and how they chose to interpret that language. Therefore, Rick chose not to bring it up as he had not seen anyone charged with "manufacture" at that point, and did not want to give the authorities any ideas.
That said...Like animal pointed out, "conversion" is not the same as "manufacture."