I'm not sure what you mean by muddled, there is plenty of MF3 info available in the General section in several threads. People have gone out of there way to make sure it is out there. Though I do understand your situation and why you missed it.
My main question to you is...are you saying you were able to ODIN back to MDB, MDL, or MF3 while you were on MF3? Because, so far, that is not possible. There a couple of possible fixes that have helped a few people, but ODIN and Kies firmware flashing isn't available yet. So I'm just trying to get some clarification to what you are saying.
SGH-I337 (AT&T) 32GB
P-ROM (1st Gen.), De-Odexed, AMDL
Auto-LOKI OUDHS CWM
Make sure you read and understand the "PINNED" threads in the "General" and "Q & A" sections of the AT&T S4 forum BEFORE you ask for help. Use the forum's "search" function to find posts with additional information. You should not expect others to help you if you haven't tried to help yourself first. Also, read, understand, and follow the "XDA" rules.