You're dead right Joe. Over engineered without compromise. What makes the body even simpler to weld is the fact that it's metallurgically identical from one end to the other. So no hard spots or metallurgical nightmares to fall foul of when welding - except linear contraction after welding. But that can be calculated in mathematically. Really envious of you US owners and wish I could do/see/aid in such a project. What an experience.
I agree with Joe about that feared notion of 'body stretching' It's unfounded due to several reasons that were related a year or so ago when the subject cropped up in relation to L1A1 rifles.