What year handles are we talking about?
My recommendation is to work with Superior in C'dale. I've seen rechromed handles done by some of the other shops locally and their work is inferior to Superior's.
Here's the process.
You must first do a complete disassembly. Lock cylinder has to come out and the wafers and springs out of the lock cylinders. Then the chroming shop strips off the existing plating. They will sometimes leave some copper since removing it isn't necessary. Next you have to bead blast the handle thoroughly to remove the oxidized metal everywhere including at the bottom of the pits. Now comes the fun part, sanding. Most of the small pitting can be removed with sanding, but the big ones should be left. This is the difference between the good shops and the others. Other shops will grind down to the bottom of the worst pits, changing the shape and profile of the whole handle. In one case a shop made a genuine handle look like a repro!
It costs more $ to fill then sand, but then the part still looks original. To fill, they do a quick copper plate. On that they use solder (must be lead free) to fill the pits. After they are filled, file then sand smooth. Next is the copper buildup where they plate a thicker layer of copper that will allow them to polish. After the polish is nickle, then chrome.
The cheaper shops will not do the soldering to fill. Instead they just grind away.