After reading all the advice and chatting with Warren I'm going to spray a good PVA release layer and then fix any imperfections in the tooling gel afterwards. Shame that I hadn't realised celly paint is incompatible but mega relieved all is not lost! For future plugs I'll be using pattern coat primer to avoid this issue.

I am in a similar boat to you Shinobiwan, I can't spray 2K. I use 1K stuff to paint all my plugs, and they come out fine using PVA. I have destroyed a couple unfortunately, but that was before I started spraying the PVA. I don't necessarily count coats, but what I normally do is spray a few (2 or 3) very fine mist coats, then I go over it with heavier coats as if I were spraying a paint. So by the time I' done, I will probably have done 2-3 mist coats, and then 2-3 heavier coats. If your PVA is anything like mine, it won't look perfectly flat at first, it will have some tiny air bubbles in it. But these all disappear after 5-10 minutes, and leave a very smooth surface. Spraying it on this heavy will make it pool in tight corners and radius' though, so have some paper towel handy and just stick a corner into the pools and let it soak up. Or use it more sparingly in the corners. It will also take a little longer to dry, which you can speed up with a hair dryer or a heat gun, but just be careful not to cause bubbling with the heat as that will come out in your mould. 

Hmm, that's a shame about the paint since I spent a bunch of time buffing them but definitely don't want things sticking so that'll have to be addressed before anything else can happen. Would it be possible to use pattern coat over the celly? If not then I'll have to go with the PVA release, how many coats would you suggests is thick enough?