Workshop Outletts on Metal Conduit
I ended up riveting the boxes to brackets and bolting those to the existing &quot;grain bin&quot; bolts holding the Quonset Hut Hoops together.  Then ran EMT through them anchored to other bolts via P-Clamps.  An important note:  The boxes need to be secured rigidly, not merely hung on the conduit and supported by conduit (this would not be allowed)
I posted a picture of the final configuration in the question.