Complex sentence: This was formerly a (metre gauge) line throughout its length from Volos to Kalampaka, however the track from Paleofarsalos to Kalampaka/Meteora is now (standard gauge).
Split into simpler sentences: This was formerly a (metre gauge) line throughout its length from Volos to Kalampaka. However, the track from Paleofarsalos to Kalampaka/Meteora is now (standard gauge).