External Display becomes main during mirror

Is there a way to get my built-in laptop monitor to be the master when I use an external monitor?

I have a Mid 2010 MacBook Pro running OS X 10.10.3. Everything is working well. I have tried to mirror on two different external VGA monitors (only connectors/adapters I have are firewire), with the same result. The external monitor works fine, but it becomes the main display. I really wouldn't care, except the resolutions are different, and some applications need the MacBook Pro's 1280 x 800 resolution. Sometimes I am able to get the Built-In Display resolutions, sometimes not.

In System Preferences, I choose "Displays" then there is a dialogue, "Optimize for" and I have to choose either "Built-in Display" or "VGA Display." When either is chosen, the resolutions underneath change to match. For some apps I need a VGA resolution, for some I need the Built-in resolution. Almost invariably, it seems to get stuck in VGA resolution. The correct resolutions appear, but the display does not change to that resolution when chosen. When I do not mirror, or unplug the VGA monitor, the Built-in resolution corrects itself, but when I plug back in, both monitors flip to the VGA resolution. Every now and then it will go back to the correct built-in resolution when chosen.

I looked in About This Mac/ System report, under graphics/displays, and as you can see in the attached screenshot, the VGA is the main display and master mirror, while the built-in is the hardware mirror. Is there a way to choose which is the master? Or another way to be able to go back and for?

Thanks for any help.

Displays: