Ok so you now have all of the information that I have.
Unfortunately I don't have any pictures of type 1 or type 2 radiators in-situ, to prove my theorem. Perhaps others have some pictures that they can post.
What I do know however, is that Salesman Bob apparently purchased Natrad's final tropical core off the shelf a couple of years ago for the SA museums carrier, meaning that all recores in the future will have to be made as required at a rough price of $1200.
I am still saving for mine. :dh:
Finally, here's a radiator in place in carrier 5000. Not that you can see either the overflow pipe or the bottom outlets.
Pedr
PS Tony, Tropical cores are about 5" thick and have a tapers on the front face 3" from the edge on both sides. Ordinary cores don't have the tapers and are only as thick as the sides of the radiator ( approx. 3" ). see Eric's first picture in this thread.