The Farm I worked on for years had two full time mechanics just restoring tractors. Had one of the best collections in the world until one brother died and then they split it up and sold some off. The remaining brother opened a Museum with some of his collection.
http://www.aghistory.org/
Including the first diesel Caterpillar ever sold.
http://rides.webshots.com/photo/2066...77698672sMnuag