Gerry, just think how good it will be to have that clean under-the-dash
feeling.

I also have had to replace the fan switch after wasting an hour trying to
repair it, the thing just flies apart :(. I also had a "funny" smell from
my heater when it warmed up. Wasn't the sweet smell of coolant, and it
would fade after about 5 minutes. Now I think it was something growing on
the heater because after a few months of constant heater use the smell is
gone.
I would use sealant when rejoining the two halfs of the system.

Alistair