Board Thread:Questions and Answers/@comment-25122904-20140630120440/@comment-7451135-20140731154103

possible solution:
 * check what's your current Jules contract
 * search the buyback shop for "Mechanicon" (bottom left corner)
 * holding your mouse at the lock/buy button, you'll see the conditions, like limit and Jules' contract #
 * so now you should know what's the problem: you need a higher contract or if your limit is maxed (e.g. Limit 6/6) the wagons are in your storage

some thoughts:
 * if you didn't finished contracts 14 and 16 yet, you never had Mechanicon Gravel or Cement ->you can't buyback them
 * maybe you sold Mechanicon Glass or Steel ->look in Buyback Shop for Mechanicon Glass and Steel
 * maybe you didn't sold them (e.g. you canceled it) so they are still in your inventory ->search for "Mechanicon" in your Storage