I am helping a friend restore a 65 fast back. It came with a 4 speed transmission that the Previous owner was going to use to convert it. Can anyone tell me more about the transmission? The #s on it are C5AR7006-DW-2 there is also a plate riveted to it with "RUGM and 013159 on it. He is thinking of keeping it original but he wants to know more about this transmission. If he does sell it what is it worth?