Based on the really bad hinge weld shown in this photograph, I'd look very carefully at the remainder of the construction.
This is a MIG weld and has almost zero penetration as shown by the convex, blobby shape of the weld. If you look carefully at the top of the hinge weld, you can see it has not penetrated the base metal and there is a gap between the weld bead and the base metal.
In reality, these are the wrong hinges. I understand why they used them - they're cheap. Weld-on hinges are about $20-$25 / pair.
The welds were done "cold" (not enough amperage) probably because the wire was too big. They used the same diameter wire they've used on the thicker metal. The weld at the top of the damper plate frame is OK (not great, but good enough). You can see penetration on all sides of the weld and the weld bead is flat - but, that is because the metal is thicker allowing them to turn the welder up to an appropriate amperagae.
For the hinges, need to change to a smaller wire, turn up the amperage and not worry about the edge of the hinge. What they really need to do is just let the hinge metal melt into the weld. Of course, that takes a steady hand and a lot of practice so the weld is straight and the hinge metal melts evenly into the weld bead.
If the remainder of the unit is built with the same hit-or-miss fabrication techniques...it may not be the screaming deal it appears to be.