Obviously I cannot show any brands or logos.. whats an easy way around that? I was thinking about printing out some logos on glossy sticker paper just enough to cover the logo/name and still look like its part of the can.
Maybe find a local microbrewery and ask if they'd allow you to use some beer bottles as props. (I know you said cans, but maybe bottle are OK?) They get free advertising, you get free beer. Everyone's a winner.
I was talking to an older friend and he said when he was young they literally had generic "BEER" cans just like that picture. You could buy them just like any other beer.