Can a siezed brake caliper be rebuilt? 83 240D

[Carrameow]

I pulled my 83 240D Bendix Brake Caliper today. The outside piston is stuck in place and I couldn’t pump it out when I removed the pads and applied brake pressure,.
I have two questions:
1. Can this Caliper be rebuilt?
2. Could I interchange two 82 240D ATI calipers I found at a junkyard and are rebuildable?

[sbourg]

Try tapping the stuck piston with a brass tool to free it. If you can't remove it, the issue is moot. You may find the surfaces are pitted with rust. You can buff them with emery cloth, but if the piston is chrome plated and the surfacing has deteriorated, it must be replaced.

Steve