A large number of the welds were put in while the two pieces were attached to each other. This assures the part maintains it shape.
Areas over the flanges of the back panel were not welded if at all possible. This prevents accidentally welding the two parts together. There was one spot where the weld made contact with the flange below. A couple of twists freed it.
The penetrations were pretty good. There are a few spots where I will back gouge and weld in order to minimize the risk of a crack propagating from areas of incomplete penetration.
I have found that Dremel 409 cut off wheels mounted on a Dremel tool do a good job of making a helpful gap for penetration on 18 ga.
The last of the welds joining the old and new metal will be completed with the parts separated. Then they will be rejoined and the regulator mount will be created.