On the welded plates, looks like backyard welded job, not very good and scrap metal. Nothing on other side of the frame. Used to have a wood flatbed, even the "U" bolts were made with 2 bolts, 1 bent other welded to the bent bolt creating a "U" bolt. Guessing was a farm truck. Assuming the plates were for the flatbed or something else.
The helper springs are bolted onto a plate onto the frame, see last photo. Not planning any large loads, just a nice driver in town.
Just got a job requiring sand for a filter, gives me an excuse to go pick up filter sand, sandblasting sand and a hose that will complete my blaster. May just blast away.
Will post the overloads on Driveline just to be safe. Maybe someone can give me ideas.
Thanks Again
