Dyes for Pinatype Process?

While I was reading the 'History of Color' I came across the pinatype process.
( here is the link to the pdf book http://www.archive.org/download/historyofcolorph00frierich/historyofcolorph00frierich.pdf )

It is a three color transfer process that uses dyes imbibed on an exposed dichromated gelatine plate ( DCG plate ). Each color is transferred to a final support in a fashion that sounds similar to carbon transfer, except the gelatine matrix ( for lack of a better word ) stays on the plate and only the dye is transferred. So you can repeat the process and make multiple prints from a single set of plates.

Anyone know what sort of dyes might work for this? The original dyes seemed to be proprietary. Or should I be researching other dye transfer methods for clues?

This would be a neat addition to my tri-color gums.

If the gelatine on the matrix is fully hardened ( KCr will do that, as well as other agents) and only offers a physical relief that varies the amount of dye that is allowed to lie on the matrix, prior to impressing the paper on it, then just about any dye should suffice. So offset printing might be a place to look.

This is all theoretical.
I am not a great pratictitioner of alt processes, but am keenly following it for the time after this full time plus job ends.

I'd try the dyes used for Kodak's dye transfer process since this sounds similar.

Robert, I'm going to look into what it takes to get dye-transfer dyes. I don't know if Pinatype dyes were ever disclosed, but you're right that Friedman says they are proprietary. It'd be nice if there was a disclosure in the intervening half-a-century, but it's probably a case of lost knowledge, protected while it was commercially viable and then forgotten.