Northport Nailer or Yeck?

[Hillside]

I have a bunch of Northport Nailers and Yecks (smooth) but I can not tell the difference.  Is there an easy way to distinguish which spoon is which brand.  I believe the cup of the Yecks become flat but it is hard to tell.  

 

Thanks!

[Gill-T]

Northport nailers have a twist in the blank.