Thanx for the info, Aaron. I had done all that you advised, even taken it to my local "mechanic", to no avail.
This time I heated (with propane torch) the surrounding boss around the bushing, taking care not to melt rubber bushing. This time I used a bigger cheater bar too, for more leverage. Problem solved now, with bushing seated correctly. I did bend the arm on my bar clamp though. It`s still quite serviceable still. That`s little price to pay for a vexing problem!