Combining .adx files into .afs archives?

[vsp]

I'm interested in tinkering with the sounds in some of my Dreamcast games, and have hit one roadblock -- I can extract .ADX files from .AFS archives and convert them to .WAV or MP3, but I can't find a program that'll compress .ADX files back into an .AFS archive.

"afslnk" is hinted at in a variety of documents, but I'm getting 404s looking for it. Anyone know where this (or an adequate substitute) may be found?