Newbie Prusa 3d printer help

Hi I bought this printer, could you tell me what model it is. I think its missing some parts and some bits are broken. Could do with seeing a complete one. Is there a reprap firmware configuration for this printer. Have got the web interface running and the servos, fan and tool heater working. How are the metal bushes supposed to stay in the plastic parts on the z axis? Is there a trick to ensuring the nuts for the z axis screws are level? Is the z axis endstop switch supposed to be positioned so the nozzle stops just above the bed?