Jay,
>Let's say that I want the buttons on the main about form to instantiate my subclassed buttons rather than the actual codebook buttons...
One of the recent changes to the framework (Version 2.07) was to allow a developer to specify different classes to be instantiated for all of the forms that are pre-built in the framework. In the particular example you mentioned, you could subclass the About form (or create a completely new form, make the desired changes then set the application object's cFormAbout property to the name of your new form class.
For more details, check out the section in the Developer's Guide called "Subclassing Built-In Application Forms".
FYI, in the soon-to-be-released version of Mere Mortals, we have opened up the framework even further by adding an "Abstract Factory" to the application object to instantiate classes. If you are unfamiliar with this design pattern you can get more details in the new version of the Developer's Guide.
Regards,
Kevin McNeish
Eight-Time .NET MVP
VFP and iOS Author, Speaker & Trainer
Oak Leaf Enterprises, Inc.
Chief Architect, MM Framework
http://www.oakleafsd.com