Great - it sounds like the link between the courses was a fortunate accident. Thanks for looking into this.
I was thinking about the abandoned courses issue, and I think it’s probably best to do nothing, i.e. no purgatory list and no course deletions.
By simply copying over all the current community courses to Decks (including clearly abandoned courses) and waiting for occasional requests from users to become contributors, a ton of work will be saved. The only downside is that your data storage (which is presumably fairly inexpensive) would contain a bunch of old low-value courses.
From memory, I think @Lien was dealing with requests only about once a month from users who were wishing to become contributors to suspected abandoned courses. Just a suggestion, but could this be a minor task you’d be able to take on?
Thanks, - Ian.