Rare Vacuum Grip No. 4 Ignition Pliers

[rocklander]

Acquired a set of small nickel plated Vacuum Grip ignition pliers and find they are marked No.4. At first I thought they were the more common No. 5 set until closer inspection showed the No. 4 mark. There isn't anything I can find on this model in early SO catalogs, this site or Alloy Artifacts. I'm guessing it's a model offered briefly before the No. 5 was introduced. The No. 5 is found in the No. 60 SO Midget Utility Set and was offered for many years by SO. Anyway, here are a couple photos with one showing the subtle differences between the No. 4 and a No. 5.