I'd say the UI elements is the easy part. I don't know how you'd add the CD tracks. I'd also recomend adding an option to disable both in the settings for those whom find the DOS assets more nostalgic.
Also, I know the DOS/Classic Editon is included just because and not many actually play it, but do you think you could implment GUS support? Looking Glass promissed a patch but failed to deliver for the CD editon, and the "official" GUS AIL3 patches glitch out and stop playing on certain levels. This would be great for those whom had GUS cards and want a trip down memory lane.