The original FFIII soundtrack has 44 tracks, but the tracks seem more cut up in this new release. For example the Final Battle and Ending are each 3 tracks, whereas they're 1 in the NES OST.
The tracks DO loop on the original OST, though not all the way in some cases. Keep in mind they're rather short tracks to begin with. The first battle theme is about 40 seconds prior to looping, and also tacks on the victory theme for a grand total of 1'53" for the whole track.
Original OST is 54 mins 32 seconds. This one is probably pushing for the pure maximum of over 70.
Edit:
Wow, check out the samples on the main page:
http://www.square-enix.co.jp/music/s.../ff3/info.html
Pretty damn impressive for the DS. Though I'm assuming the sample quality was reduced for the actual game. This must be pre-compression.
Jam it back in, in the dark.