Chuck, I wrote the S03 on the heat tubing before I realized it was the wrong part - it's not an S03. It might be an old version and now that I don't have to send the "wrong" ones back I'll cut the tubing and see if the board is similar. It might be the same as the S03 but with the triac tucked in and a spare ground wire that can be cut - that would be nice!
Regarding smoke fluid, yes, saturated. I've got the loco apart and took apart the smoke unit and disconnected one side of the resistor to confirm it's 8-ohms, and while I was at it I took out the wick and pulled it apart more and fluffed it back in. No need to replace as it's brand new with just a touch of brown from my testing. The resistor is getting some voltage, but not enough to produce more than a polite suggestion of smoke.
I plan to post a summary of everything I've learned once I've got the new unit installed and *hopefully* working. But it will be a few weeks.
