As I’m figuring out how to do things I often find that I sketched something and extruded, but I want to change the sketch, and redo the Extrude. It seems that the two are separate, so if I move my splines, the bodies stay unchanged. Can I delete a body somehow without loosing the sketch it was made from?
SORRY! The Clips are not playing I will redo them and get right back
Having remade the Clips they still do not function ON THIS PAGE although run fine elsewhere.
Rebooting my Mac resolved the problem.
@thepian
Sketches, in the form of Closed Shapes, can create a Body.
When Bodies are created they are immediately separate from their Sketches, just Delete the Body the Sketch is untouched:
If your Sketch is complex and you need to make alterations use Design Thumbnails to create a Duplicate, and then work with the Copy version:
NB. Remember to tidy up after making the alteration Rename or Delete as appropriate before you get ‘buried’ in Designs.
I am now going to Delete all the ‘designs’ created to hide my work 
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