Gemar Melacha regarding immersion of utensils (tevilas keilim)

I received a sandwich toaster, and during shipping the metal plates separated from the plastic. It was not possible to reattach them with screws, since the screw bases broke. I therefore drilled into the plastic in order to fasten the screws. My question is: does this count as gemar melacha (final completion)? Because technically, one could still use it even without attaching it to the plastic — it would just be very difficult to open and close, since there would be nothing to hold on to, as the metal is boiling hot.

Shalom uVracha,

This is an important and significant repair, and it exempts the appliance from immersion (tevilah).