Hello, I’m concerned that if I build this gate using two chain link hinges on the existing post in the picture that it will sag and not be strong because the two hinges would both be at the top of the gate. I am also concerned that I shouldn’t be putting holes in the aluminum siding for the latch because they will rust. I also can’t put post in the ground due to the concrete. How can I add a gate here. Can I drill into the stone wall and put anchor hinges on it and then use the siding as just a latch somehow? Thanks.