I put together a quick simple caveman mirror service, and mirrored all the repos in this post to: jME (Archive) · GitHub (please double check)
If you resurrect more repos, please PR them to the list here:
they will be added to the queue.
The syntax is simple: One https cloning url per line followed by an optional #originaluser to override the repo owner name (just like in this case, where we want them to say mirrored from jayfella/XXX in the description and not from your github handle).
I will eventually attach this to the store, so that it can create a private mirror of every repo we have there, so that if this happens again, we can evalutate if the repo can be restored (license, reason of deletion etc) and eventually make the mirror public.