I've been messing around with this for a while and I can't seem to find the connection between fcurves and the specific shape key values they control.
I can use something like the following:
bpy.data.actions['KeyAction'].fcurves[0].data_path
to get:'key_blocks["sitFix"].value'
But how do I get the shape key list that "sitFix" is in?
bpy.data.shape_keys['Key'].key_blocks["sitFix"]
i.e. 'Key' in this instance
Searching by name doesn't look like it will work, as Blender allows different shape key blocks to use the same name within different shape key lists, so there's a 'sitFix' in both 'Key' and 'Key.001'
Ultimately, I'm trying to see which mesh is being affected by a particular fcurve, but here I've hit a break in the chain connecting them.