Hi!
The article by Allan Thayer (a relative of the Beethoven biographer?) appeared in issue 16 of Wax Poetics, April/May 2006, pp 88-106. Six pages consist of photos of album covers and compact labels, and the back cover is covered with small pics of Brazilian soul albums. This issue also includes an interview-article on União Black. The illustrations in the Black Rio article are credited to an Alberto Forero and I've found nowhere in the magazine any reference to Almir Veiga, the Jornal do Brasil photographer. The Frias article gave rise to a series of responses in the mainstream press, including one in the New York Times and articles by Julio Medaglia in Folha de São Paulo, 10 June 1977 ("Black Rio assusta o maestro Julio Medaglia") and by Gilberto Freyre, in Estado de São Paulo, 30 May 1977, all duefully scared. Even Veja, 24 November 1976, had a feature.
There is a good article by Bryan McCann in the Journal of Popular Music Studies 14 (pp 33-62, 2002), "Black Pau: Uncovering the History of Brazilian Soul) and another Wax Poetics issue (8, Spring 2004, 124-29) has a beautifully illustrated feature on Simonal.
I have posted a bib on Brazilian Soul and Baile Funk at
http://cpalombini.wordpress.com/generos/baile-funk-e-soul-brasileiro/bibliografia/Please, let me know if you intend to keep the Frias scan at a permanent location, and I will link to them, if you let me to.
Cheers!