ummm, ok, well that was interesting
After formatting a new SD card and re-imaging it with the latest version of Jessie and then doing a fresh install of Cayenne (edit: using a new set of install commands) low and behold all my sensors (DS18B20, BMP180, TSL2561) loaded themselves and named themselves the names they previously had prior to the OS becoming corrupt. And the dashboard was all set up, and all the data seemed to be available. As seen below-
I go back some time later and the BMP and TSL are no longer there , as seen below.
So I was very surprised to see the old information populate without any interaction on my part, made me think the Cayenne servers look at the hardware serial number as opposed to anything that is on the SD card. But when the non-auto discover sensors went away again its like the mother ship decided “oh wait, this is almost the same but not quite”.
Sure glad I got the first screen grab when I did.