Every single pice you see is from the original planes.
Not to nitpick, and definitely not picking on you, but... No, not every piece you see is from the original. The majority cannot be hammered out our straightened out to a point where they retain their strength. The more you beat a piece of metal out of shape and back into shape, the less strength it has. They will tag certain pieces for re-use, but typically non-vital things and not load bearing ribs, frames, structures...
You don't go from this:
to this:
by pounding out a few dents and just bolting it on. You create those from scratch. The translated article even mentions something along those lines on one of the image captions. The reason these restorations take years is because they are measuring the parts and hand-fabricating replacements and hand-assembling them.
Or do you think they're taking shattered remnants like this:
and just welding the shattered shards back together? Doesn't work that way.
From everything I've seen on restorations from various nations on various sizes from single seats to massive bombers, it's a very painstaking process whereby you strip it down and replace shattered and broken parts with hand fabricated new parts, thus replacing the weakened and/or missing parts from scratch. New metal, new strength, but built to old specs. That's what a restoration is these days. Essentially the Flugwerk Fw190 has as much in common to the original Fw190 as some restored planes do. Same plans, same design, new metal.
It's nice that they have the engine blocks for those Jumos, but getting them running is another matter entirely. We didn't have any DBs for many decades because while we had the engine blocks we literally could not build or fabricate the parts we needed with modern technology that they did back then. All the jigs and parts and stores of materials were gone. We literally couldn't fabricate a new camshaft, for example, because it just wouldn't fit or work in an old WW2 engine. I would say Jumos might be a little easier than DBs, but a wrecked engine sitting around for 76 years is not going to just start up if you clean it.