EGFxSet: Hegel Pedroza, Gerardo Meza, Iran R. Roman. CC BY 4.0.
https://zenodo.org/records/7044411
https://creativecommons.org/licenses/by/4.0/
Modified: sample selection, low-pass and 24 kHz/16-bit conversion.

FlameStudios: Gary Campion; SF3 conversion by gdm-2112. GPL-3.0-or-later.
Modified: MIDI bank/program numbers only.
Original editable SF2 sources and license:
https://github.com/gdm-2112/electric-guitar-soundfonts/tree/main/SF2/FlameStudios
SF3 sources:
https://github.com/gdm-2112/electric-guitar-soundfonts/tree/main/SF3/FlameStudios/std_muted_mod
Exact conversion script: prepare-guitar-sounds.py (included alongside these files).