Using ATC model codes to identify ATC/Deco Tel sets

[RotoTech99]

I have found a number of ATC practices with the model, feature, and identifier codes for sets such as the Cradle phone, Chest phone, Candlestick, and the Character series sets that shows how the model codes were "put together" based on the components used.

What I have difficulty with is a number of my Deco-Tel sets are older than the practices, which date primarily from 1974, and don't include modular connector information/codes as part of the practice(s) covering it.

I have found typically that if I'm already working on a Deco-Tel set I have data on, assembling the model code is pretty straightforward, where it confuses me is when I work on one that has both Bell and ATC model code data, but is one built with WE as part of their Design Line. Which code is best to use to identify it?

Has anyone else found ATC/Deco-Tel literature that would update what codes are best for identifying certain Deco=Tel sets? I hope to see this updated in the future.