Originally Posted by first-model

Phil, these are great questions. I don't think anyone has ever really drilled into this, so it may take a bit of time to get more precise answers.

Based on the invoices I've looked at, I think the product codes date back to the mid-1970s when computers were coming into use. Prior to that, a gun would just be listed on the invoice as a Model XX, followed by any details about the configuration.

I'm looking at an invoice from 1976 for a delivery of 30 Model 27s to the Austin (TX) Police Department, and it shows a product code of 0272043530*. The "027" at the front is the model number and the remainder forms the product code.

How product codes and SKU numbers intersect is a bit of a mystery to me. I have some invoices from the early 1980s that have both of them on it. I don't see that one is numerically similar to the other.

The AS400 mainframe came into use around 1985, and the guns in that are tracked by the usual six digit SKU number.

A wholly inadequate answer, but hopefully that scratches the itch a bit.

Mike