I realize that this thread is over four years old, but I had the same exact problem a few years ago. The left side spindle broke off just below the washer welded to the spindle where it goes into the axle. I found a pair of used spindles on Ebay, but they were from a different break in serial numbers and were metric instead of inch and wouldn't fir the axle bushings or wheel bearings. Sooooo, I found another set that were correct and bought them. They were the correct size and worked fine.
I think it's a poor design for a piece of bent metal rod to support all the weight the 430's have on their front axle. That is one reason I never got an FEL for it, the front end just didn't look like it was up to it.