Patty,
Joe is 100% correct. I do Jewelry plating (silver, copper) but the concept is the same.
some advice...
1. Try looking on old car boards (they are one of the biggest users of this service)
2. Try looking on old boat boards (they are the second most common re-platers)
3. This process is not cheap mostly because of the labyrinthine regulations and permits required.
(one of the most toxic processes in manufacturing)
In most cases it is cheaper to buy a unit that to re-chrome. If the part is rare, it is worth it.
Also, there are some good "chrome" paints being sold that with hand touch-up work can make an unsightly spot less noticeable.
Lastly, if you let me know where you are at i can help you locate a service (Private Message if you'd rather)