If one were doing a reduced pressure distilation of 2 solvents, with a manometer connected between the vacuum pump and the recieving flask. Would one need a valve to prevent the solvent from deteriorating the manometer's accuracy, a filter beween the system and the pump, or would one need an aspirator to create the pressure difference?

To distillate the low boiling solvent (less than 100 deg C) under reduced pressure use aspirator pump and valve between manometer and system. (If you use oil pump, you need cold trap to condensate solvent vapours)