I dove into the cooling system R&R head first today, and got the removal done, I think.  A question for the list.

As I checked out my long pipes, I saw that the rust was only in the engine compartment.  Everywhere I could check, forward of the cross frame member (where the jack point is front of the rear wheel) the long pipes seem okay.

I took a sawzall to the pipes and took off about 18 inches.  I am thinking about replacing this section with hose, and leaving the greater part of the long pipes in place.  OTOH, I could be persuaded that I should junk the long pipes altogether, and just go for a long run of flexible hose.

Do any of you who have removed these remember if there was other rust, under the gas tank for instance, that I may be missing.

Once again, thanks for all of the list's help.
Peter and a slightly dis-assembeled Zippy