In the wiki for the scoring of Best Manufacturer it states
You get points for manufactured products.
Basis of calculation (norm. production costs * amount produced)
Does "manufactured products" mean "All End Products" (as on the Market page in the game) or anything that you manufacture such as semi-finished products like Steel, Copper Wire, etc.
Also
does "norm. production costs" mean Normal Selling Price on the SUDE or Production Cost as published on the wiki for each product.