There is a panhead screw for the Big Boy smoke unit that is unavailable on the Lionel parts sight; it is item 6 in the list on this web page:
and is part 6402542198 SCREW / PANHD / 1.9 mm X 8.0mm x .4 thd
that is used to secure the PCB board to the reservoir. Does anyone know of an alternate source for it??? I lost one but would really like to obtain 5 if possible.