Talman’s Texaco Star trade magazine is online in a full 1913-1963 run, in archival scans at the University of Houston, Texas. This was the official free internal monthly magazine of the Texaco oil company, which he edited from 1930. The run appears to have been placed online in March 2021.
Sadly it can’t be searched across in full-text from a single search-box, and there are no TOCs alongside each issue. But scholars know that it was, under Talman’s editorship, home to some items linked with Weird Tales contributors. There’s a story about Everett McNeil which features him as a character, for instance. Lovecraft talked himself onto the mailing-list by the end of 1930 (for the historical and travel articles), and also considered how he might contribute travelogues. And here’s the Robert E. Howard article from April 1931. He doesn’t get the cover, but I’ve also included the front and back cover for context.
There’s also talk in the Talman letters about a forthcoming Providence article and map in the Star, though I haven’t got that far in the book yet.