With 497's rebuild completed in 1967, i've often wondered why it didn't see any use in 1968? Was it being saved for the silverton, or for impending scrapping operations on the n.g.? Or were they just using up remaining flue time on the other locos (483, 484, 493, 498). Did 493's flue time expire in mid 1968, explaining it's lack of use late into the year? Or was it just luck of the draw?