Why use a fig file to store data? You shouldn't be storing data in a fig file, just as you shouldn't be storing code in a mat file.
If you want a reset funcitonality you will have to make that yourself by storing the initial values during the startup.
I would encourange you to read this thread. You will also find an example of how to implement this in a class. How to implement it in a GUIDE-created GUI is a bit more tricky, as you'll have to hard-code which objects and parameters to store.