Downloaded BRG 2 from the full list site and found a folder containing each track as flac, and all the same files as mp3, after listening to them both I couldn't hear much difference between the flac and the mp3, I performed a spectrum analysis using Audacity and it reports the same results for both flac and mp3, the result showed what you'd expect from a flac file, but to have a similar result for the mp3 was odd, so going by the details showing while hovering over the flac files indicates that replaygain was used encoded by FLAC v1. 1.4a with FLAC frontend v1. 7.1
The plot spectrum analysis results as mentioned earlier for both the flac and mp3 were approximately 22000Hz.
Question is, would you say that the flacs are more likely to be fake in that it was no doubt the mp3 files that were used to make these flac files which would mean that they aren't true lossless files, so you'd be best to keep the mp3 files and ditch the flac, after all they both come to the same analysis.
With regards to the mp3 files they were encoded with Lame Front-End 1.8 using pazera software.