I have that article on Knoebels, too. I am pretty sure that most people in the Pittsburgh area didn't even know that park existed when it was published in 1984. The Phoenix was attractive because it was in good condition, as the weather is different in that area compared to other areas. The Knoebels are in the lumber business, so the had a 'inside track' on how much it would be to replace anything.
The rule of thumb, from what mechanics I know say, is that you can lose up to 25-30% of the wood, when the track is removed. They all believed that it could not be saved. Always lay new track.
Plus, it is an established ride, so to speak. There are exisiting operating permits, blueprints, maintenence logs, etc. You know what you are getting into. That is the norm for even steel coasters. You have a history of things you need to know, like how long ago the lift chain was replaced, how often do you need to change brake pads, rebuild trains, etc.
Parks often fall into the cycle of buying a new steel or woodie and not being able to afford parts, carpenters, etc. Its like if you have an older park, and you buy a Huss flat ride. Now, you have to send someone to Huss school, get credit with their parts distributor, or be at the mercy of an independent Technician who will hit you for like $500/hr, plus expenses.
Of course, as everyone has discussed, its the added marketing ploy that bigger parks could use to hype a ressurrected ride. The Racing Whippet from Pittsburgh's West View is added to Idlewild. The Dips is reborn at Kennywood, The Wildcat from Idora at Conneaut Lake, Knott's rebuilds the Long Beach Cyclone, well, you could be here all day. Maybe I will start my own company and rebuild the classics? Any investors out there?