If you only had a few items, I would recommend the use of balled up aluminum foil and water rubbed on the chrome. It works amazingly well. Google to learn more.
With such a big stash of stuff.. I’m sure others will have better recommendations.
Cleaning with citric, phos or acetic acid, Evaporust or sodium citrate is a lot easier for a lot of tools, but if there's rust under the chrome it will lift the chrome off, often leaving sharp edges.
The rust isn't "on" the plating, it's on the base metal and coming thru voids that corroded away over the decades. I'd try a quick soak in evaporust and then keep them oiled.
And all "chrome plating" is hard. Chromium is just behind diamonds on the hardness scale; there is no "soft" chromium.