How to restore a default size of the created buttons(custom plugin of Qt Designer) on the form? Rebuild ui file with default parameters of widgets.

I have created a custom plugin for Qt Designer it simply QPushButton class with corrected size of button that creates(modified default values of the size), but if i have a many forms with this buttons(with different size each button) and i need to restore their size to default (wich previously was generated in ui file when the button is created) it is possible? If possible then how? I could provide any information if needed.