The hangers were a source of cranial turmoil for me over a period of time. First of all, they were worn out, had been repaired, and as Mark pointed out - subject to bending. Analysis revealed that they are 1025 steel castings. Were this not a historical restoration, I would have replaced them with 4140 or similar material, but since they are easily seen I decided on repairing them in kind. It could be argued that they served reasonably well for 50 years in much harder service than she will see going forward.
The design is sort of nifty in that it eliminates hangers between the wheels and the frame, thereby negating the possibility of the paper-thin outside hangers we found on #346.