To be honest I can’t remember exactly what I did in the end. It was a couple years ago. If I had the same issue now I would just rely more on the Waveform Monitor to tell me how bright it really is.
You might try exporting a few seconds of it to a different codec, and see if you don’t get the same results. Also try using something other than (Adobe?) Media Player to view the final export.
You are comparing the original corrected footage in premiere to the encoded footage in Media Player right? Throw the encoded file back into Premiere, and see if that looks different played there. Hopefully that will help you narrow down where this issue is coming from. Good Luck!
Logan