[jerryhawthorne]

Oh my Kirk where does one start to answering these questions? Well, a posted schematic:

http://www.nostalgiaair.org/PagesByModel...013216.pdf

Please blow this up and look at items 66A (10mfd) and 66B (18mfd) The two caps you have selected will be fine. Please also note that the can you cut off for installation has a cardboard tube around the base to isolate the can from the clamp which is screwed to the chassis (hence ground).
Looking at the underside of that can there should be a tab attached to the base of the can, that tab and the two "internal" connections in the can represent the three leads you now have as shown.
Tricky and I may be wrong but the negative of the 18mfd and the positive of the 10 mfd should be attached to whatever attachment there was on the underside of the cap going to its metal base. Again this tab should not show direct (zero) resistance to the chassis.
This leaves the 10mfd negative and the 18mfd positive going to the two feedthrough connections. You will need to trace which goes to which based on following the schematic. This is assuming you have not removed the wires from the bottom of the cap.
I hope this helps. Hint, the 10mfd negative will go to chassis ground.
I will leave the other questions to someone with more patience and understanding.
Good luck! Jerry