Picking up drilled tank - What do you think

Hey all,

I'm picking up a new (used tank) but the problem is it was drilled on the top of one of the sides. It looks like it was just plugged with a bunch of silicone, but I haven't seen it in person yet. Assuming I wanted to reseal it just to be on the safe side, what do you think the best way would be?

Could I just scrape off the silicone that's on there now and just put a bulkhead on it without using silicone and cap the end of it? I know many people find a slightly larger piece of glass or Plexiglas and just seal it with silicone, but that seems more difficult if I can just slap a bulkhead on there.

Any help would be greatly appreciated!

awesome, thanks. Any recommendations on where I could order the best bulkhead? Do people typically seal the "washers" with sylicone or just use threaded bulkheads and then cap it?