Installing Kelsey Hayes Caliper Pistons ?

Hard to say what kind of corrosion they had sitting around for 16 years - maybe just some gunk holding them in the cylinder, but also our friend named Rusty may have paid a visit. If they look OK after you get them out and inspect them, then yes. I think you will have to look carefully in the seal grooves - any big pits in there would be a point where I would consider new ones.