Between oreillyauto.com and advance auto, three different brands of ignition switch cylinders, none of them had this hole threaded for the T15 screw.
I don't have anything in my SAE tap set matches and I don't have schmetric yet.

 

It looks like this. That's what I bought for my 95 and it works.
https://www.ebay.com/itm/19221001519...mis&media=COPY

 

You could take the screw to ACE hardware, match it up to find out the diameter and thread pitch then buy two taps, one of them a bottoming tap.

 

True, and I might end up doing something like that if the NAPA version is messed up too. And there seems to be some sort of crazy tap shortage with both my Home Depot and Lowe's being completely out of taps, Auto Zone has a set that is too large.

Other people might wish to know about this parts problem before they show up at the parts store, since multiple brands are identically messed up.

 

The schmetric strikes again

 

A dozen sellers of single taps on eBay - at least there are here.

 

Another Ace Hardware had the tap, but my Harbor Freight tap t-handle wouldn't tighten down enough so I had to use pliers.

 

Another odd thing.
This is my original factory starter switch assembly. The hole there is where a pin is supposed to be.
I replaced the module prematurely a few years ago and was going to reuse it, but I couldn't pull the pin out of the Standard brand unit.
Didn't find it in the box it sat in for years, and don't remember finding one rolling around in the floor.