Hi Ross,

If it was feasible, having a swap over babbit head would be the ideal solution, then you could use whichever one was perfect for the job.

On your first pic, the one with the drill, if you go to the top right, you will see the vertical and horizontal joint lines between the apron and saddle. If you slacken off the apron bolts on the top, you should be able to insert a shim at either end of the vertical joint. I would use a couple of coke can shims, and by doing that, the apron should be moved away from the rack.

If that didn't work, as far as I can remember, the troublesome gear is just held on the shaft by rough peening over. By the marks shown, it looks like the gear isn't square on to the shaft. There would be no harm done if you just took a file to the gear and reduced the high spot until you got no fouling. Maybe try this before shimming.

not pretty but hopfully functional
Ross, paint doesn't cut metal, so just being a bit scruffy means nothing, you can slap a bit of paint on anytime.

John