Do the forest hex and the pasture hex that receive Oil Spring tiles still produce lumber and wool?
Oil Springs
No, after the Oil Spring tiles have been placed on the hexes, these hexes only produce oil.
May each player only upgrade one of his cities to a metropolis?
Oil Springs
No, a player may build various metropolises. However, in a 3-4 player game only four Metropolis tokens are used for play. Once the supply is depleted, no more metropolises can be built.