I mix from scratch for convenience, but recently acquired a lot of darkroom materilas from an associate who is now disabled, and is liquidating his darkroom. In the pile of stuff were 4 metal cans of D-19 developer powder, packaged up for the Canadian air force on a contract dated 1964. Well, last night I was working on a bit of black and white slide experimentation to make up masks to title some head shots, and realised I had the d-19 already on hand for the called for d-19 +thiocyanate first developer. So I peeled the tape off of one of the cans, and pulled the top off. The hydroquinone in one plastic bag was a little bit grey, and the bag of carbonate and bromide was a bit lumpy, and needed crushing before mixing to break the big lumps up. But it mixed up just fine, and develops the film just as though it was mixed from fresh chemistry. I also mixed up 5L of fixer from an old kit of Agfa 60 colour developer kit that I think is for ep/2. The packet of companion part A of the blix, the amm ferri ETDA was missing, so I have just been using it as a black and white fixer. It is quick; it clears film in under 2 minutes, and seem to do a fine job in fixing RC paper as well. It seems to also be very viable in terms of capacity. Everyone I know around me loves their latest camera phone/ digi thing. But how many of them will still be workable three years later, let along over 40 years later.