[irjwxfxf] Reinserting someone else's content

In Freenet, is it possible to reinsert someone else's content so that the original CHK address works?  The scenario is, you've downloaded a file, keep both file and the address you accessed it at, later try downloading it again out of curiosity from the same address, and notice it is no longer available.  As a public service, you would like to reinsert the unmodified original file at the same address.

I suspect this is possible but am not aware of tools that make this easy. For larger content, I think we also need to match the original FEC settings.

Going slightly further, the client already has a default "downloads" folder.  Let the client always constantly reinsert content in your downloads folder.