It's difficult to do legitimately, because British copyright law changes have (from what I've read) been retroactive made Life+70, and they're collective works. So, for a particular comic to be in the public domain, everybody who worked on it would have died prior to 1945.
As a reminder, if anybody has more specific information on copyright law in any country, we'd love to hear how we can figure out what can and cannot be shared beyond the United States. Like, if there was some point in British history where copyrights were fixed-term and the law has never been extended backwards to cover them, that would be great to know!
