Forum:Official sources that are not officially hosted

Opening
First, a little context: as part of my hobby of making in-universe pages for super-hyper-specific things from the real world, I recently made three new pages: one for the Radio Times issue owned by a parallel world Mike Yates, and another RT issue and TV Times issue owned by Paul Magrs and his mother. I used timeline clues in order to track down the exact issue numbers of these publications for use in their conjectural titles.

For the two RT issues, I found the issue numbers thanks to the BBC's official archive; as such, I cited them as external links on their respective pages. I want to do the same for the TVT issue but the source I got it from is complicated; it comes from the issue itself… via an unofficial scan on an independent magazine archiving site.

Are official sources that come via unofficial avenues like this allowed to be cited? WaltK ☎  21:12, 28 September 2023 (UTC)