Pin Assembly Pivot

I am restoring a 1953 TO 30. The bolt in the Pin Assembly Pivot does not seem to be right. What am I supposed to have?

The bolt should screw into threads in the front axle support. If it has the original front axle support the bolt should be 5/8″ fine thread as I recall, with a shoulder to prevent it from being screwed in too far. The axle pin and the bolts came with different size holes for the bolt. Is it possible someone replaced the original pin and bolt with one with a smaller diameter bolt? The other possibility is the threads in the axle carrier are stripped?