Small piece for my car

The part I chose to remake is pretty rare on my car model in the UK & sourced this from the Netherlands, since I'm on the uk owners club I have had a few people on there asking if I would also make them a copy of this part,

So... 1st up I made & glued the flanges to it, figuring out where to put flanges to make the mould the easiest shape for releasing is a bit confusing at times, managed it 2nd time round,

Then I used the yellow filleting wax & did my best to create a good draft angle all the way around, next step was the mould release wax, gave it a good coat, waited 5 mins & then buffed it off with a new clean cloth,

After this I mixed up some gel coat & applied a layer, this is where the problems started, it seems to have reacted & separated in places, any help/tips on what to do next would be great, or do I have to start the whole thing again?