In 1989, I had almost every chromed piece on my TR3A re-chromed. They charged me $1200.00. They had a lot of work to do straightening my bumper. About 8 years ago, after about 50,000 miles, my bumper had some deep scratches caused by a dump truck which had shreaded a tire and a section got flung at the front bumper where the wires sticking out the tire did the damage to my bumper. The same shop wanted $1000.00 to re-chrome the bumper.
This was a chrome shop run by some really nice Harley guys but new environmental disposal laws had forced them to increase prices. Ask bikers in your area who does nice re-chrome and a reasonable price.
As for the new retro bumpers for the TR3A, they are not the same as the originals. If you have an original, get it re-chromed. You say it's for a TR3 and they only have the repros for the TR3A. The original bumpers have the curved wrap-around where it curves to conform to the curve of the fender and it curves all the way around. The repros curve but not enough. They stick at each end out like wings. They look good to the ordinary person but if you are serious, you will see the difference.
Mine is the black one.