4-pin vs. 3-pin

[BigAl62]

Could somebody post pics of a 4-pin and a 3-pin side by side? Does the lock bar pivot count? I've mostly collected fixed blades and have just recently started to look at some larger folders.

 

[BigAl62]

So I'm posting these here in response to my own question. The one on the granite surface I lifted from the Bay. The one on the green mat is mine. If my research is close to right, the 4-pins were made up to some specific date - maybe 1984 or so - and the 3-pins were made from then until the start of the Taylor era and have continued since. I did see one answer on another site that suggested that Schrade provided 4-pins in response to loss warranty claims but I am a bit skeptical of that.