It has been quite a few years, but as I remember the damper rods were hollow, with a "funnel" like taper at the top. I was always able to spin them loose with a pneumatic wrench, but if that didn't work for you, I would try a long screwdriver, or steel rod with a flat ground on the end to wedge into the center of the rod, after you verify the hollow taper of course.
A lot of seals have a steel ring near the outer circumference of the seal to add rigidity and many times the ring has a lip, you might try to drive the screwdriver at an angle to the outer circumference of the seal then pry with a twisting motion, the combination will many times walk the seal out like a tire machine removes a tire.
As for the nicks, careful work with a stone first to remove the high spots, then some very fine wet sandpaper (1500 grit) should do it. If the nicks are deep, Devcon makes specialty metal filled epoxies for this type of repair. I have some if you should need a little, pm me and I can send enough for a small repair.