Question about Irwin-Pedersen slides for rki
 

I have seen Irwin-Pedersen slides with the number 2 marked on the left side commonly. I often see S'G' slides with letters on the left side. Yesterday I saw a picture of an Irwin-Pedersen slide that had the letter A on the left side.

Were Irwin-Pedersen slides marked with A on the left side used in a particular serial number range?

I have an IP slide with the stamped A, although I can't answer your question I will be curious if you hear an answer.