4 Speed Tunnel - Is it factory?

I recently acquired a 65 Barracuda. The fender tag says it's a factory 4 speed car, and the hump in the tunnel looks factory original from inside the car. The factory seam sealer is still intact and the paint looks totally believable.

But when I look under the car, the cuts that were made in the side of the tunnel before the 4-speed hump was installed look very rough, like they were made with an acetylene torch. I've never seen the bottom of a 4-speed tunnel so I don't know if that normal.

Also, some bonehead cut the cross member. Don't know why. I also don't know why they tack welded a piece of sheet metal to cover the shifter hole.

So how did the factory install the 4 speed hump? Did they start with a narrow tunnel like an automatic car, and then cut big holes in the side of it with a torch? Did they use the same cross member as the automatic cars?