Source for axle control leaf bushings – 66 Imperial?

So I can't find a picture in my manual - but I'm looking for a source for replacement bushings for the forward-mounting leaf springs that control axle wind on the Imperials. The seat in a bracket on top of the axle, and a bracket on the floorpan (under body). Looks like they press in like the larger leaf spring eye bushings...
Need a source for them - any ideas?
Author: moper