1. I take all of the unecessary stuff I do not need out, all of it just for weight and handling purposes, the pumps and motors are usually locked up and do not work anyway.
2. If the dents do not come out feel free to use bondo or whatever body filler you prefer to use.
3. I use Kroil oil on the computers. Spary it thoroughly and keep working it with a pair of channel locks, it will eventually free up.
The main thing is that this is your pump, restore it to the max or min, whichever way you like it because it is your pump. Post some pics when you are complete.
Thanks, Phil