Ok, a slight amendment to these Ives images made with the HiCro camera.
On page 60 of Frank Roy Fraprie's How To Make Prints In Colors (available here on Google books) are instructions for the Hess-Ives color process.
It appears that these are not dye-imbibition prints afterall, in the sense that there's no transfer of the dye, though there is imbibition into reliefs by dye-baths, but they are on thin celluloid films that are then superimposed.
The instructions are pretty unclear, but it seems that the relief films are pre-sensitized, as there's no mention of a sensitizing step or anything. And after a hot water etch, they are put into a hypo bath, followed by clearning in a potassium ferricyanide bath, which is somewhat puzzling to me.
There are instructions and different 'tabloid' dye capsules for either transparencies or prints on paper. The transparencies would require a higher dye-content than the paper prints.
In summation, I'm somewhat confused and obviously need to learn a bit more about this HiCro camera and process.
So, did I really see dye-imbibition prints or not?!