>Goal: sub-class the form controls toolbar
>
>I copied the _base.vcx files to a local directory for development.
>I then referenced this class in Tools\options... This successfully gave me a a new controls toolbar and I can modify methods with the class browser. I made a specific change to a grid.
>
>However, when I drag a table onto the form from the data environment, it doesn't reference my current class library. What part have I missed.

You have to change the association fr VFP between Grids and tables - set Tools/Options/Field Mappings for the item Multiple to point to an alternatative Grid class than the base grid.