The parts came in a day early and I've already started. I had to sand the front of the stock just a little bit to get it to fit up to the tube cover and line up with the hole. It'll be at it's farthest point, but that's fine since I'm 6'3". I can still see the peep just fine, but I am able to raise it up more so I'm not craning my neck down as much when lining up the sights.
It's obvious now that the Gen 2 tube has a slot in the top, back portion for the buffer to slip in. The Gen 2 locking mechanism is attached to it so there would be no other way they could accomplish this. Since it's not going to lock anywhere I'm either going to cut off the lock or just use the factory buffer.
The Gen 2 buffer body by the pin hole is smaller which allows the Gen 2 stock pin to lock in place. I could modify the the factory buffer, but I'm determined to use the new pieces and leave the Gen 1 factory parts alone.
Now it won't close all the way with the stock extended all the way out. If it's in the smallest/forward position it would close and the sight would be right behind the stock. This is fine, but either the cover needs to be removed since the top of the stock goes well over the charging handle slot or I'd have to cut the front of the stock down.
I'm not sure which way I'm going to go yet, but it would function just fine with the factory buffer,the slightly sanded down stock and new stock pin like in the pictures below. The only thing I would wonder about is how well the stock pin would stay in place. It's a tight fit and takes some effort to remove, but it's not totally locked in.