I don’t have a Brian May guitar or external Treble Booster, but my guess is that you’d like the darker 58, 421, 906 or U47 Blue captures for that kind of sound. Without the guitar, I don’t have a reference to give you more specific recommendations, but I’ve definitely felt Brian May vibes with my own guitars. If you get the Pack, try the 2A, 2B, and 2G positions with the 58, 421, and 906 mics. Try distances 3 and 4 with the U47 (probably C3 or G3) and see what works the best with your hands. And don’t be afraid to blend IR’s.
This is when I wish people could just come to my house and we’d dial in tones together. Makes it so much easier than guessing. And I also with I had that guitar. I bet it sounds really unique.