YouTube's great! I have found a 5 minute video of Kirk Hammett of Metallica who was showing some riffs to a couple of their songs from Master of Puppets. After almost two decades of my playing those riffs I discovered not everything was transcribes as it should've been. Damn!
In addition to this, I got a hold of MOGG files which are Guitar Hero tracks rips. The game mostly uses real tracks that have been mixed into stems, that is groups of instrument tracks normally used for mastering. Here there are around 12 tracks: kick drum, snare, toms, high-hat and cymbals, lead guitar, rhythm guitars, vocals, backing vocals + some more. With a MOGG as hand, you can import it into Reaper (a low-cost but as professional as any other high-end multitrack audio software) and solo a given instrument to have a unique listening experience.
One of such tracks is Battery. Now the Interlude part that's haunted me for ages (I knew it had been poorly transcribed but had no idea how to improve it) became as clear as a day. I'll soon ad some transcriptions for all to enjoy.