I was just about to post this when I noticed Elizabeth's posting.
There's a huge cache of clips, about an hour of film, of BsAs milongas on Muller Patricia's YouTube channel, posted five months ago and labelled as 'Viejos Milongueros'. Apparently they date back to the 90s. I dashed in, hoping to find Ricardo Vidort, Muma, Portalea, Gavito, Tete, Elba Biscay... and was sadly disappointed. They show BsAs milongas all right, but the dance is the dance of people who enjoy social tango, although from what little I've seen perhaps it's not the tango of Lo de Celia or El Beso, or of what I think of as the 'old milongueros'. However, every now and again a couple slips past the camera with such easy grace that you think, 'Who was that?' Lively, good-natured social milongas – and good lighting too!
If anyone watches Osvaldo Natucci on Practimilongueros, be warned: there's a slight mistranslation. He divides dancers into artisans and aficionados, but the subtitles translate 'aficionados' as 'amateurs', which is misleading as it can suggest people who aren't very good at something. I think he'd call dancers like the social dancers in Muller Patricia's clips 'aficionados', rather than artisans, who are a bit more obsessive about their dance.
If anyone watches through all that film and comes across any of the 'greats', do let me know. I recognise one venue, La Ideal, and possibly one or two others, but I think there's film from several more. Patricia asks for any information anyone might have about the milongas and the people.