All pictures dated from spring 1964.
Picture of George and Astrid: "Astrid at George and Ringo's rented Green Street flat in London.
Picture of John (there is another one of John actually playing the guitar. I will have to scan the picture to show it in here): ' John plays guitar at his and Cynthia's London flat.
There's a couple of more pictures of George playing guitar as well (including the one with Ringo on the background), but they're not as good as the one already posted. There's also another picture of Ringo with the guitar, fooling around somewhat.