Here is a smoke unit mod you could try.
http://www.tuveson.com/hybrid-...id_smoke_element.htm
Also I use a Mouser part # 594-AC01W30R00J 30 ohm resistor in my MTH smoke units
I carefully tap off most of the soft ceramic coating to expose the nichrome wire.
It is a one watt resistor that does not soak up the heat as much as Lionel's 3 watt versions therefore is more efficient.
594-AC01W15R00J is a 15 ohm that you can use to replace the 16 ohm ones.
Carl