Shot in a Zero Image 5x4 (I made a "plate holder" from foamcore & cardboard, but no darkslide) at EI3 - about 4 mins exposure.
Developed by inspection in some goo I made up a couple of months ago to test something for someone else and didn't throw away (phenidone and coffee in glycol)
I'llhave to try and work out a way of making some sort of inserts for my 5x4 holders for them. My temporarysolution has to be put on and tken off the camera under red light or ina drkbag. I could use blue tak or dble sided tape but i really don;t want to make too much of a mess of the holders. They're not cehap.
From my small collection of "out of date" paper and films. Yes, that is a pack of Ilford Multigrade before it made it to MG II, possibly 1960s vintage (batch number 1305H).
The Ilford plates are even older - Judging by the steamship roundel, 1930-45 vintage.
the plates in my OP, by the way, appear to be military issue; while googling for info I found a pdf of Admiralty Fleet Orders from Novmber 1942 noting that these (Pattern 2698) supersede and are preferred to the previous warmtone plates as the blue-black colour provides for superior projected images. They were to developed in a universal developer for one and a half minutes.
When I can be bothered I'll knock up some ID36 and see how blueblack they are after nearly 70 years