We haven’t found a way to decode how properties of the MSChart control are stored in the .frm form. To correctly migrate this control you should load the original project in the VB6 IDE and run the VBMP Project Dumper add-in.
The VBMP Project Dumper is a VB6 add-in that adds a new command to the Add-ins menu, which - when invoked - creates an XML file containing all the properties of all the controls in the project. You need to invoke the command just once, before attempting the migration process. (You need to invoke it again only if you modify one or more properties of an MSChart control in the VB6 project.)
Even after generating a dump of all the properties of all instances of the MSChart control, however, a few properties aren’t migrated correctly, for example all the properties related to the BackDrop object.
You can work around this limitation by manually assigning these properties via code in the Form_Load event handler.