Hi Norm,
Sorry, I was not precise enough. In my previous post I was refering only to flat-bottomed "C" catches subcategory, and agree that in this case it's very hard to tell individualy without a risk of being wrong. Only a number of individual opinions may secure its correctness or long years in this hobby which I lack, unfortunately.
Here is another opinion from Mike's great article:
http://members.iinet.net.au/~datumgeo/Schwerin-Article-Sectioned/7HingePinCatch/Schwerin_HSF-HingePinCatch.htm
Cheers,
Hubert