I've never ran into that before. If you switch the bushings around, you're going to have to do both bushings so that the control arm can't slide back and forth on the bushings. How far off are the actual mounting holes from lining up with the control arm? Rather than doing a bunch of cutting and welding, I think I'd spend a few minutes with a chainsaw file and just open up the mounting holes in the chassis a bit in whatever direction they need to go.