I brought that 1929 article to George Vrechek's attention back in 2005, and he gave me credit in his original article. I also posted about it here on Net54 in 2015:
http://www.net54baseball.com/showthread.php?t=202129
I know there was a newspaper article in 1930 about baseball card collecting, in which the rarity of the T206 Wagner was mentioned. I don't have a citation or a scan handy, but I know I've seen it. I know there were some other newspaper articles about card collecting and specific collectors in the late 1930s and early 1940s, because Jefferson Burdick mentioned them in Card Collector's Bulletin, but I haven't tracked them down yet.
Apart from Burdick's articles in Hobbies magazine in the 1930s, and then Card Collector's Bulletin starting in 1939, I'm aware of two articles about card collecting that were published in the popular press in 1945. I've posted about both of them here:
1945 Sporting News article on baseball card collecting:
http://www.net54baseball.com/showthread.php?t=238775
1945 Esquire article on "The era of the cigarette card":
http://www.net54baseball.com/showthread.php?t=219020
When T206 and most of the other 20th century U.S. tobacco cards were issued in 1909-1913, there were lots of newspaper articles mentioning the card-collecting craze among young boys. Some of those articles have been posted here, though I can't find the threads right now. What you're looking for, I take it, are early articles about (tobacco) card collecting by adults. I would expect those to be easier to find in the U.K. than in the U.S., because card collecting became an organized hobby over there much earlier than it did here. Undoubtedly one factor in that is that your tobacco companies continued issuing new cards up until World War II, while we just had two relatively brief bursts of tobacco card issuance, in 1887-1890 and 1909-1913. But it seems to have been seen as at least a respectable hobby over there from at least the 1930s, while here it was kind of an underground thing, something to be ashamed of, until the 1970s, and really until the 1980s.