Rust Removed, Rubber Safe
As you might have already expected, the Rusteco Liquid did the job, completely removing the rust and saving the rubber. The cracks you see in the rubber were already there before it was de-rusted. As a side note, I noticed no change in rubber hardness by pressing on the bushing by hand and the surface of the rubber actually seemed more natural and supple (not hardened OR softened and spongy).
Rusteco Liquid Application Image Gallery | Image 9 of 13