I was finally able to remove the front attachment bolt on the rear spring. Looking at it, it appears it was not rust that was giving me so much difficulty. There seems to be a fine rubber coating on the portion of the bolt that goes into the spring bush and this made it difficult to remove. It's not on all of the bolt. This does not show in the illustration in the service manual. I'm sure this will make it harder to get the attachment bolt back in. Should it be there and is it necessary when replacing the bolt?