Following on from the picture of the Webley 1000 .177 pellet box, here are a few pictures of a full 500 .177 box from the same period, with the penciled in price of 1/4d still visible, and a couple of a later empty .22 box.
Finally, a couple of Webley .25 pellet packs, both full.

http://mynetimages.com/35cf4743.jpg
http://mynetimages.com/4a964ccf.jpg
http://mynetimages.com/08a13f12.jpg
http://mynetimages.com/e659d5a1.jpg
http://mynetimages.com/6450c98a.jpg
http://mynetimages.com/f32e078f.jpg