Ken,
I'd made a casual effort to locate the Janus Butte trail a few years ago but didn't see any obvious jct with the 559 trail. It may be there if one were to really hunt for it.
The steep trail down to Lake Lenore is easily located. The trail out to Schreiner Peak continues for a short ways past the Lenore jct along the ridge top and then disappears. I searched at various elevations for blazes, old tread and flagging but found nothing on that first attempt. The terrain is quite rugged from there to Knob Rock and out to Schreiner. Hope to make another recon out there soon and will report if I find anything.
Dan