All of the bits I needed to complete the heater rebiuld arrived this week.  Included was a plastic bag of bits of foam to make seals inside the box, but it wasn't immediately apparent which bits went where.

Inspiration struck; I'd ring Rob as I knew he'd done the job on his car.

Yes, said Rob, he'd rebuilt the heaters on both his E Type and his Mk2.  No, he said, he still had no idea which bits went where.

So I glued them in where it looked like they might go.  Hell, no one will ever see them.