Quick update - I got the headlight bulb, spring and eyelet assembly and that is working ok (but somewhat dim - see below).
I got the liquid smoke replacement unit and it works great on the bench, but produces no smoke when on the track. I suspect that the running track voltage might be too low to drive the liquid smoke element (28 ohms resistance). The engine runs best at about 9.5 v (as shown on the Z-4K) and will derail on an O-31 curve at 11 volts.
IF the heater element requires more voltage, then I'm not sure if this issue is correctable, so I may have to get a pellet-type element.
