You can fill the holes. It won't be perfect but not a hole anymore. Heat up a piece of scrap and drip if into the drilled out holes. Don't let it get too hot that it gets soot in it. If you think about it (and after you watch out work in real life, not on your head) the water pressure (which is a lot less than you would think) is pushing in on your system. You only really need the hardware you seeking to keep it together until you build the pressure and for all the times your not going straight ahead. The bracket I use on mine to keep the gate deployed uses a thin rivet on its hinges. I was going to replace them with stainless bolts but decided against it because 1- they have held up through all my r&d and 2 (the biggest reason) they are a fail safe. If for some reason I hit something , forget there deployed and take off our go took fast in reverse I believe they will fail, alleviating the pressure before other things do.