Complex sentence: The production run was very small (circa 1000 copies) however when this run was sold an alternative version was sold that was missing the track breaks i.e. there was only one 67 minute long track.
Split into simpler sentences: The production run was very small (circa 1000 copies). However, when this run was sold an alternative version was released with no track breaks, i.e. there was only one 67 minute long track.