Complex sentence: These were shipped to the bridge's present location and re-assembly began in 1968, with the original stone being used to clad a concrete structure, so the bridge isn't really the original it is modeled after.
Split into simpler sentences: These were shipped to the bridge's present location and re-assembly began in 1968. The original stone was used to clad a concrete structure, so that the bridge is no longer the original it is modeled after.