I'm having a hard time adding a variable fillet to the outer edge of a surface model.  The model will only let me increase fillet size to a small amount and I need to increase it to as much as ~.75" in some areas.  I've done some digging on the forum here and I believe it has something to do with my boundary surfaces, but I'm not too sure how to remedy the issue.  I'm new to surfacing as this is the first model I have made using any surface features, so I apologize in advance.  The part is attached with what I have managed to fillet so far, but I would like to increase the fillet size to the sections already filleted and add more definition as shown in the attached photo.

Thanks