Not sure which is the right section to post in, but it's certainly not product availability! I recently acquired 5 packs of unexposed Autochrome plates, 3.25" square, these are 4 to a pack so a total of 20 plates, expiry date March 1913, all the same batch. Sufficient to actually make some experiments with exposure & processing.

Base camp 1 is to find out the state of the emulsion, and I used 2 plates to do a test strip, and then from this a full plate exposure, under the enlarger to a test transparency. Processed to a negative in Ilford DDX 1+4, as that was to hand. The surprising thing is that the emulsion is not only recording an image, but that the fog level is not too severe and the plates may actually be usable, as a little colour was revealed on this test.

So the question here is, has anyone been down this route before? I had a quick trawl through apug searches but couldn't find anything directly relevant. With a limited number of plates, if the experimentation could be kept to a minimum there would be more material left for actual photography, (if that were possible).