I realize that the game happens in an alternate universe, so not everything is going to be the same as it was in ours, but it seems that the idea is to make it as much like the real 80s as possible outside of the big tech changes.
With that in mind, I want to point out that the Hemenway Walmart described in "I, Wagner" would never have existed. Walmarts in the 80s were not grocery stores, they were discount stores. No Walmarts even sold groceries until the late 80s (Supercenters) and Walmarts that exclusively carried groceries didn't appear until the late 90s (Neighborhood Markets).
A better choice for an iconic American grocery brand from the period and region depicted would be Safeway. Unfortunately, it wouldn't resemble the grocery in the book at all. It would be much larger and a single story. The kind of grocery depicted in the book didn't really exist in the US anymore by the 80s outside of corner groceries in the inner cities, at least not as part of a chain.
So, if you want to use the information in the book with as little change as possible, while still maintaining an historically accurate feel, then it's best to not make the store part of any chain, and instead have it be "Welch's Family Grocery" or something similar. A holdover from an earlier age. Otherwise you'll need to change the physical descriptions.
This isn't the only anachronism I've found in the US localization of the adventures in the book, but it's the one that stood out to me the most. I'm guessing that Matt Forbeck just wrote the chapter on the US Loop, and didn't localize the adventures as there's things in there that anyone who grew up in the US would likely catch as being out of place. Like Public Libraries here don't close during the summer, they actually tend to get busier as they ramp up summer reading programs for kids, including those 10 to 15!