At 1732 eastern time, a Cessna 210M on a Part 135 cargo flight was damaged during an emergency landing at Lunken Field. The pilot was not injured. The pilot said he was approaching Owensboro, Ky., for landing when he selected the gear down and his right leg was sprayed with hydraulic fluid. The gear down-and-locked light did not illuminate. He aborted the landing and circled while he and ground personnel tried to solve the problem. He then diverted to Lunken Field, where the charter company has a maintenance base, where ground personnel were able to see that the main gear were dangling. He secured the engine and landed on runway 07, but the airplane veered off the right side of the runway and was damaged. Inspection revealed the left side hydraulic line installed from the gear handle to the gear power pack was ruptured due to contact with the rudder interconnect cable. The Cessna 210 Service Manual revealed that there were no defined instructions as to how the rudder interconnect cable or hydraulic line should have been installed, nor did it provide clearance limits for the two components.