I found enough pyro to make a batch. You'd be surprised at how good such a simple developer can be. In a sense, it is older by far than this old man, being closely related to the Pyro-Soda developer which Hurter and Driffield admired. Soda, of course, is sodium carbonate. Here's a sample of FP4+, 1+50, 77 F. (It's warm in there.)