How could we find out if there was an increase in the ink trade because of the printing press? What would that mean? What effects would it have on our understanding of trade between
countries we have studied leading up to this time?

Assemblies do not have written codes of laws. laws are matters for magistrates and courts, not assemblies. codes of law are things such as civil law, criminal law, and constitutional law. what assemblies have are procedures regarding debating, voting and other business they might carry out.  also note that rome had three assemblies: the assembly of the soldiers, the assembly of the tribes, and the plebeian councils.