The key now is to set your stall out & do achievable areas and start as you mean to go on. The best part is that having discovered things, you can start the positive.
Clean area, jacked up and over a tarp or similar.
White sprit and several stiff brushes.
Go easy with any wire brushes as you don't want to take off any galvanising
Clean one are at a time
Have a box of rags etc handy
Use whatever replacement underseal you opt for (clear would ensure you know which parts you've done if it's days/weeks between starting & completing)
Overalls, glasses or goggles
Patience & a sense of humour
Copious tea breaks and a radio channel of your choice.
Part of the owner/car bonding process
