Just replaced all my vacuum lines and found that I have one tube coming off the...? (see pictures) that is not connected to anything and I have no idea where to attach it to, it also has a very small amount of oil coming out of it.

It's the top center tube

 

Hmmm. That tank isn't ringing any bells with me. Looks like some sort of add-on judging from the big hose clamp holding it in place.

Cheers
DD

 

The only aftermarket thing that the previous owner installed (that I know of) is an aftermarket cruise control system which I started removing as it never worked. The car runs fine without the tube connected to anything, it's just annoying that I have a dangling tube that's dripping oil.

 

That looks like the standard cruise control unit just mounted differently? Are you sure that is after market?

 

I had an aftermarket control unit in the cabin and the person I bought it from told me her husband had one installed. I can't see any OEM cruise control switch in the cabin so I'm thinking the car didn't come with one originally. I wonder what'll happen if I just remove the entire thing.

 

probably would be just fine as long as you plug the hose ends