Exhaust down pipe & gasket replacement

~2009 Mitsubishi Outlander 2.4L, 4-cyl~ I heard an exhaust leak under load (when accelerating). Went to a local muffler shop to have it checked out & repaired. They said it was not worth it at this time as the leak wasn't that bad yet & would possibly require more exhaust parts as it is all rusty hardware & brackets. They also mentioned the down-pipe was a dealer-only part & would take a long time to get. I believe them because afterwards I went to the nearby dealer & it was on back-order, for several months (2020 - might be something about a pandemic). In the video, you will see the upper flange coated with white stuff. That was/is muffler repair cement which I tried to use to verify that the donut gasket was leaking & not the exhaust manifold or down-pipe. I figured if the sound would change even for a few minutes after I packed the space between the down-pipe & manifold that the donut was at fault, however it did not help me with that task. You might also notice that the heatshield around the old pipe has been mangled a-bit. I was trying to see if the pipe was cracked or rusted out somewhere in there. None of my prior attempts proved successful so it all had to come off anyway. I looked online for the down-pipe & gaskets. I found two places where they had aftermarket parts in stock, checked everything into the cart & compared prices including shipping. Decided to buy from the least expensive online store as I do not like paying excessively for shipping charges (even though they are sometimes included in the item price with "free shipping"). Once the items shipped, I soaked the rusty hardware on the old exhaust with penetrating oil (PB-blaster) everyday after returning from work to free up the rust & possibly prevent breakage. One fine Sunday afternoon, I started on the job to replace the pipe & gaskets. The new pipe has the heatshield tack-welded while the original part had it bolted together. But as you can see, that heatshield was not going to stay there much longer. In fact, lots of the heatshields on this vehicle have fallen off or are barely holding on. When I hear one rattling, I try to wire it on to keep it longer or just pull it off completely.