Here are some pics of the new reciever.
If you decide you want to go with a non chrome lined barrel we can get together and you can use my chamber reamer. I can make some different spacers for it so you can get the headspace you want.I'm looking for a barrel for my new M25 receiver. Not sure what I'm going to put on this one.
The hole you refer to is used as a datum, representing a line that intersects perpindicular to the bore line center of the receiver ring.Yours looks a lot like mine except they forgot a big hunk of steel in the back GI8. Have you noticed the hole in the leg on the side that has the mate for the trigger group spline. (pic 2) I seem to remember this being discussed here before, but I am not sure. That hole is not there on any of my other recievers. I do not see its purpose.
Anyway it sounds like you have great plans for her and she will have a cousin in Tenn. Sometime next year I want to get a real nice stock for mine and eventually a good scope. For now I will be happy to get her to the range. I thought I would build it this weekend, but my honey-do list got in the way.
Great PIcs thanks for posting!