Hmm.. Only five messages allowed in the inbox seems a little stingy!
Got the Doc, very useful..
I will look into the smoke unit, and a couple of other things and report back..
I have used a DPDT relay board I made up for a USA trains Alco S40.. Had the same problem with the LED commons.
I cut tracks on the original board to allow the switches to be used as well as DCC control. Used a function output to switch a second relay (again, in series with the switch) for smoke.
Thanks again,
Phil.