Hi,
The inspector can edit properties of a model only. The paper is a view.
You can edit the graph (the model of the paper) with the inspector, but we do not store attributes like zoom, origin on the model (because you can have multiple views of the same graph with a different zoom level).
Here's the trick.
// Create a Backbone Model:
m = new Backbone.Model();
// When a property on the model change update the paper property
m.on('change:x', m => paper.translate(m.get('x')));
// This is how you manually set the origin-x
m.set('x', 6);
// Now you can open the inspector for the `m` model and create e.g `range` input for `x` coordinate,
Best,
Roman