Thanks for all the info.
I've just reinstalled SH3 on a new system and I'm getting ready to add GWX and whatever other mods look interesting to start out with. I'd only had the game for about a month before getting the new rig and hadn't got beyond the Academy and a couple of uneventful first patrols. Hadn't even scratched the surface of everything that would be possible especially with mods installed.
I do have quite a bit of music in both .ogg and .mp3 formats already that I was hoping to add to the Gramaphone mix once I really get going with it - was just trying to decide if it was worth converting .mp3 files to .ogg before adding them in. Seems like maybe the .ogg format may be a bit more stable.
I do still want to make sure that it's okay to delete/replace any Gramaphone files that are installed with the stock game and GWX. Also I seem to remember that the ones that came with GWX had file names that started with 01, 02, etc., does that indicate a "track number" that has anything to do with the order in which they're queued when you play the Gramaphone in the game?
I also want to echo other sentiments I've read in the forums here about how welcoming and patient everyone is with newbies like me. Does a lot to keep one's interest in the game and site alive and kicking when info and support (and general kamaraderie) is available in such a friendly atmosphere.