I have been doing vast research on the subject and have come up empty.

What problem are you having?

Here are some thoughts. First, backup your save game.

- You could try copying the subhood template into your save game. That might help you to see the neighborhood to package the lot. Be sure to backup your subhood template first, since the game may want to modify the template to match the one in your save game.

- Use SimPE to change the witch lot to residential and to find the lot number, copy the now-residential lot package to your LotCatalog folder and rename it to match the naming conventions in the folder. The lot should now appear as a residential lot in your lot bin.

- Use the loadLot cheat to load the witch lot, the changeLotZoning cheat to change it to residential, then change it to visible in SimPE (I'll try to find a link). At that point, you should be able to use one of the first two suggestions to package the lot.

Here's the thread about making hidden lots visible:
http://www.moreawesomethanyou.com/s...hp?topic=9750.0

Another thread about editing hidden lots:
http://www.moreawesomethanyou.com/s...p?topic=11323.0

Note: I've only given a general overview. If you need more information about anything, be sure to ask.

I have seen both those threads, actually.

What I cannot do, is turn the lot into a residential one.
Nor will SimPE allow me to save the subhood.

What method are you using to turn the lot into a residential one?

What do you mean: "Nor will SimPE allow me to save the subhood."? Are you getting an error message when you try to save?

There are several reasons why SimPE may not be able to save:
- The file or one of the parent folders has been marked read-only. You can fix this by removing the read-only flag.
- You have a version of Windows which will not allow you to modify files in the Program Files folder. Many people avoid installing in Program Files for this reason. You should be able to work around this issue by temporarily turning off User Account Control.

Here's the error message.

Huh, I don't know why it thinks I have Vista. I have 7.

Oh, and I've been attempting to use the method in the third post here- http://www.moreawesomethanyou.com/s....html#msg345422

The game does allow me to do stuff with the lots themselves, just not the neighborhood.

Edit: Oh! Breakthrough! I think I was looking at the wrong file! (Although, I still need help.)

Edit2: Okay, I've converted to a downtown hood. Um, can I just stick them in my lot thingy? They're residential...

Edit3: They vanish upon exiting the hood. Maybe if I run them through sims2pack.

I doubt that packaging the lot will make the lot visible, but I suppose that there's no harm in trying. Be sure to let us know the results.

Did you remove the invisible flag in SimPE? I gave you a link to the thread. It's a simple change to the U0 field in the Lot Description. Just remove the 0x10 flag using hex arithmetic:
http://simswiki.info/wiki.php?title=DESC

I would recommend that you make the change in SimPE, then run the game, edit the lot, make a build change to ensure that the SimPE change has propagated to the lot package, save the lot, and finally package the lot or move the lot package into the LotCatalog folder.

Packaging it and running it through Sims2Pack worked like a charm. No more vanishing.

Just a clarification: you set the lot to visible using SimPE. When you copied the lot package to the LotCatalog folder (without editing it in game first), the lot stayed invisible. If you packaged the lot instead (again without editing it in game first), it worked.

I wouldn't say it stayed invisible, but it wouldn't stay where I placed it. It'd just be gone when I came back.
But onced I packaged it, the problem went away. It stayed put. Once I gave it the mailbox etc., it behaved just fine.

Although, there is something I need to check to be sure.

Edit: It actually seems they just won't place in the hood I got them from, which is fine, as I used that one because I wouldn't care if it got a little confused.