Thanks for the kind words. =)
It's doable... But in this case "losslessly as possible" would mean recompressing the audio to 4-bit DPCM @ 22KHz... And the ramps they picked for the DPCM are kind of dubious even then. So I'd keep your expectations quite low...
If that doesn't discourage you, I can send you a build of the tool for GK - maybe drop me an email (my username at alltinker.com). It's obviously very specific; I'm chipping away at a better/more general tool for a potential public release later on; also to help with my work on further improvements to the realtime repairs in ScummVM.