I am so very tired, but I completed what I hoped to do. We now have a small deck with salvaged railing.
Obviously we still have a lot of clearing away work on the old deck. Not mention the massive pile of rotted wood which now sits in my driveway awaiting a trip to the dump. But we can now safely exit our house and it is sturdy enough to last us a few more years. We checked underneath and the combination of a concrete pad and being out of the line of fire for the dryer vent means what remains is still sound.
It is enough for one day.