Posting in a Group after the Event?

Hi SI Team

I posted the following articles in a group:

http://finalbug.net/blog/entry/482-fcp-x-first-meta-steps-001a
http://finalbug.net/blog/entry/483-fcp-x-first-meta-steps-001b
http://finalbug.net/blog/entry/484-fcp-x-first-meta-steps-002a

Which means that I see the “Join Group” banner up top as in the first screen shot!
And the articles are obviously in the Group "Learn FCPX"

I have articles here:

http://finalbug.net/blog/entry/479-roles-beyond-with-role-o-matic
http://finalbug.net/blog/entry/404-in-depth-3d-titles-fcpx-10-2-part-1-of-3
http://finalbug.net/blog/entry/405-in-depth-3d-titles-fcpx-10-2-part-2-of-3
http://finalbug.net/blog/entry/406-in-depth-3d-titles-fcpx-10-2-part-3-of-3

Which I did not post in a group at the time of posting but wonder is there a way to put in the following group now? i.e. after the event?

http://finalbug.net/groups/item/17-learn-fcpx

Ditto the following articles:

http://finalbug.net/blog/entry/400-edit-in-resolve-the-fcp-way-part-01
http://finalbug.net/blog/entry/401-edit-in-resolve-the-fcp-way-part-02

Can I put them in this group here:

http://finalbug.net/groups/item/18-learn-resolve

It would be great if this would work?

thanks in advance

Paul