Require SCORM 1.2 files created using storyline to SCORM 2004. Source Files missing. Please suggest.

Only way i can imagine...is this.

Make a simple Storyline.
Publish that as Scorm 1.2 and Scorm 2004.
Compare those, so you know the differences.
Now you can try adding the missing parts to your Scorm 1.2 package and make a 2004 out of it.

For sure not easy, as there will be many dependants in the course. So you have to test it with something small...and then see if it works with a bigger course. If you can remake the course quicker...go for that.

I quickly mocked up a simple Storyline and compared the folders with Beyond Compare 4 and surprisingly little difference in the published folders. So i guess you can try this approach. 

PS: I do think the folders missing in the 1.2 version can be copied from 2004 without problems.

Thank you Math! Will give this a try and get back if I need any help. Thank you so much for taking time to record the steps and send.