Oh dear. Will I never learn to be content with what I HAVE?
Spent the last hour playing with the "simple" answer.
Following might "do" for me...
I'm going to accept that I "need" to have all of my component references appear in the silkscreen of my PCB.
Once and for all, created in a .lib a component: VERBYREF ("VERSion for project entered BY altering item's REFerence field.) No pins. Default value a little tricky: Put what you like... but remember that it will appear in one of the cvPCB columns, so don't go mad. (KiCad puts it as upper case in some places, regardless of how I start it.)
Once and for all, created a .mod footprint: NoPin. With, yes, no pins (!). CAN call that "NoPin" and have the name survive in mixed case where I want it.
Once those are in place, forevermore I can just...
1st pass... Put a RefByVal component in the schematic.
Make it's VALUE something like "vers-12Feb-15v1"... note:
no spaces in that, and last character a digit.
During cvPCB: associate that with the NoPin footprint.
Subsequent passes: Revise component's value on the schematic. Re-save netlist
Close (if open) and (re)open cvNew
Assign NoPin to the "new" component.
Save. (Perhaps not needed. Maybe automatic.)
Close cvNew, so I don't forget!
Go back to pcbNew window. Delete the old
version-ID-giving component. Read netlist. Move
"new" version-ID-component to where I want it.
A digression: Having board edges set up... even if they are provisional... may help by putting to-be-placed things in a more convenient place that where they go if there is no board edge defined. Or maybe I tweaked something without noticing while setting up NoPin! (^_^)