Create a program to merge timestamped ASCII transcripts of legal proceedings in multiple languages

Transcripts of multlingual, interpreted legal proceedings are created by court stenographers simultaneously in two (or more) languages. The files are timestamped as the stenographers write the proceedings in realtime (see attached exemplar ASCII file).

Traditionally, the end product would be two (or more) transcripts. Because of the difference in language characteristics (and minor variations in the stenographers' accuracy), the transcripts always have vastly different pagination. (IOW, for example, the question and answer on page 14, lines 7-18 of the English transcript might appear on page 16, line 22 through page 17, line 14 in the Spanish transcript and page 13, lines 1-10 of the Portuguese transcript.)

We want to create a program that will, keying off the the timestamps, merge the transcripts so that the pagination is the same, whatever the language. The output ASCII file would have (in the example above) three line 1's -- English, then Spanish, then Portuguese -- then three line 2's, etc.