Is the formalin use as a hardener? What ever there was in the old developer, it was more consistant at getting good plates and with a fair latitude of exposure.
I wonder how the original dry tin formulas got lost, it did'nt seem to take very long to come up with them as soon as gelatin emulsions came around. Could there have been something used in the emulsion to make them work, such as a developer or a reversal material?
I'll bet someone in the Eastman establishment knows, but he aint talkin'.