Pino, I think you should use cement plaster on the deep holes. Make cement mixture liquid type and paste the liquid cement into the hole. Hopefully it'll be add nicely, so that you can later make hole to hang curtain holders.
Hello Henrik, you've shared a problem that's almost similar to mine. I've installed a guest house toilet recently. And after installing I've notified that the toilet have a very small hole and I've right considered replacing it.
I know its slightly different but here's a guide for repairing a whole in a fibreglass boat hull: http://letsfixit.co.uk/10043/how-to-fix-a-hole-in-a-fibreglass-boat/ I was looking a solution for similar problem. Very unfortunately I've made a hole in my bathroom tub as well. Therefore I looked at ...
