Maintaining Identical Document Shapes with Stencil Shapes

[MacGyver]

I have a large Shape Stencil of various custom shapes that are used in a lot of different drawings.  If I update a few master shapes (not just it's text or formatting) from within the Stencil, is it possible to ensure the master shapes within the document are identical to those within the Stencil?  And if necessary updating the document masters so they are identical to the Stencil masters.

I've done a fair amount of research on this have been unable to find any definitive results.  The only solution that I could think of requires writing a macro to compare all the masters within the document to the masters within the Stencil and if necessary copy the Stencil master, edit the document master, then paste and update the document master.

I've previously ran across this problem with shape text and solved the problem by using an Access Database and linking the document shapes to the database.  Unfortunately this solution will not work for me here.