Thanks for all the tips!

Unfortunately lots of threads on toning end with:get Rudman's book. This gets me nowhere since the book is out of print and is not easy to get! (Though I may have tracked one down at a university library an hour from here.)

i do have his Master Printing Course book and that is where I got the info about sodium sulfide vs what he calls Thiocarbamide and variable sepia toners. I'm not sure which currently available toners are Thiocarbamide or variable?