tank leaking from the top of the trim

I am not sure if the new silicone will stick to old silicone very well. I had a similar issue on one of my tanks. I ended up using gorilla glue. The company claims once it is fully cured it is food safe. I cleaned the area I was going to glue with some rubbing alcohol and then used the gorilla glue. It has been about 2 years and so far so good.

It wouldn't be that difficult to remover the top trim. Cut it off, remove old silicone and just slap it back on with fresh silicone