Is it possible to infuse over car body filler

I have made a mold I used alloy as the plug and the gel coat has come away from the alloy

Its to big to put gelcoat in so im thinking filler

The part wont be seen as most of it is under the car

Obviously don't want to make the mold again

So is this possible ?????

on one of my moulds I got some wrinkles in a very visual area (front bonnet) and I repaired these with filler, I then easy leased like mad and the part came out perfect.