Complex sentence: The buses were initially equipped with brown vinyl bench seating, but were later replaced with red fabric seats during the overhaul, coinciding with the overhaul the destination signs which originally displayed on rollsigns were replaced with digital Luminator Matrix signs.
Split into simpler sentences: The buses were equipped with brown vinyl bench seating, but it was later replaced with red fabric seats during the overhaul. The destination signs which had been displayed on rollsigns were replaced with digital Luminator Matrix signs.