the q3300a1009 is an OEM part #. Please call us with the complete model & serial # to confirm the correct part for your unit.
Yes, The Honeywell Q3400A1024 is the direct replacement for the Q3400A1008
Armstrong part R42640-001 is the current part number for Q3400A1016.
Yes, it is.
Yes it is, the Q3400a will work with the SV9570A2518.