Was doing some research this morning on bb postcards and am happy to say I think i can bring some new information to the hobby about the set discussed in this thread.
I didn't see this article by Anson Whaley from 2022 but I want to add it.
You'll see Anson has captured a lot of great information about the set:
https://prewarcards.com/2022/06/02/p...all-of-famers/
One of the things he says is: "We also do not know the makers of this set. A bald eagle stamp appears on the reverse of each postcard but no specific name or company is printed on either side."
Today we can say that the maker of this set of 6 Post Cards is The Illustrated Postal Card Company. Please see the information below:
The article and ad are from the Jan 4, 1906 Geyer's Stationer. The info on the postcard company is from this site in the link just below.
Added a pic of a couple of these postcards I used to own, just for flavor -
Hope this information makes a few collectors go, "oh, cool."

peter
http://sentfromthepastpostcards.com/...ostal-card-co/