Thanks leo, I've gone through those 2 sections, mostly I had read before, but now with a fine tooth comb, and I still can't work it out. 
There are a few mentions about moving to the folder and renaming that new folder, like the one I coded into a toolbar button above. Also a few threads about renaming parent folders from child names. But nothing about renaming a existing parent folder from child's fileinfo.
I'm not saying this information is not there, just that I can not find it, or I am misunderstanding what it is I should be looking at.
FAQ, closest threads I can find: Add the current date and time to a file's name
And rename presets, is this thread,, Sort music files and go to the target folder which is also moving, but maybe i can mod it to rename just the parent folder path so it moves into and replaces the old parent folder? Is that the way I should be trying?
Sorry probably a really dumb simple question.