…if anybody cares. 
I just uploaded the code and sample project for OGT Level Manager to github where it’s MIT licensed. You can find it here:
One of the files is a PDF with info on what’s what in the code.
If you want more info on that, here’s a short promo video:
And here’s a longer walkthrough of it:
When that walkthrough video was made, storyboard was still king, but OGT Level Manager works with Composer. Also, ignore all the links shown in the video and the docs – the MasteringCoronaSDK site is gone and the OutlawGameTools site is hibernating.
I’m planning on putting more of my source/tools on github in the near future and I’ll post a link here when I do.
OGT Level Manager worked really well for me – I used it for several games that ended up in the App Store – and I hope someone finds some use for it eleven years after it was first published.