National Stainless NS Co diamond design two tablespoons

Here are two table spoons in stainless. The back of one is marked simply "Stainless USA" while the other says "N.S. Co. Stainless USA." They are both the same. The pattern has a small diamond shape on the bottom and mid section (see close up for positive identification) but I could not find a pattern name. These are used pieces a little on the dull side with household wear but good replacements if you have this pattern.