Cool thread. Here I am, trying to find a good gig shirt, and there's Sister Rosetta, with a kick-ass gig dress. Maybe if I tried that I'd play better??
Looks like a '59 or more likely '60 GA20 for her in that clip. Hard to say. If the video size was compressed vertically, it's more likely a GA40. These have gotten pricey. Mine is ragged on the tweed, thought often of shipping it off to Buffalo Bob for a recover, then realize that would probably blow the value. Wonder how Victoria's new homage to this amp fares? At those prices, vintage value won't be negatively affected.
There are still some great values out there on the old and odd front. Ampeg Mercury is high on my list for that tweedy sortof 6v6 thing. Not as dark and swirly as the GA40 to be sure, but has its own magic. Magnatone 260 (or any other rebranded name, twilighter, panaramic, titano et al.) are just too cool. Not really tweedy. Then again, not really like anything else at all. Completely distinctive, wonderful tones in here. If you can find one, grab it, get it tuned up and put in some better speakers. Very fine stuff.
Then there are the old Gretsches. Harder to find. I would so love to grab a 6165 or 6166.
Michael D.