Thanks Monique. That sounds pretty much right to my ears. I agree that their pronunciation of Spanish words leaves a lot to be desired.

After further research, the group noted on another release (the one from which the audio file above is from [click] -- not my slightly different release [click], whose audio is not online but is nearly identical), their arrangement of the song was featured in the "A7 Songbook," obviously a songbook put out by the group in question here. I haven't been able to locate a copy, digital or otherwise, but should one surface, it would likely help identify the song's origin.