I'd like to be able to extract the same kind of data EncSpot and MP3guessEnc do (long/short blocks, scfsi, scalefac_scale, max/avg reservoir, etc), possibly eventually to try and guess the encoder based on that information, but right now I'm just interested in the layout of the data that contains this information. I've read through a number of source files, but my C is a little rusty and I'm just not getting it...

Could somebody explain to me where this information is stored, and in what format it's stored?

I take it you've checked out:

http://users.belgacom.net/gc247244/extra/tag.html

for the Lame tag spec? That's for rev0, there is now a rev1 see other threads in this forum.

Yes, I deal with the first 4/6 bytes (MPEG frame header) and the stuff that's covered in the Xing/LAME tag (if applicable), but it's the 32 or so bytes after the MPEG frame header and before the Xing/LAME section that I'm interested in, and cannot find documentation for...