Personally, I wouldn't have it done. I think K32s are among the classiest looking guns out there with the original blue finish on them. Especially the San Remo's. Put a really nice piece of wood on it and you'll have one of the best looking trap guns on the range!
I had my 32 done by Mike Crevar, Pgh, PA 412-466-3395. It was a top job. He only prepped the receiver for plating. I don't think the gunsmiths have the facilities to do plating, so they out-source it to a plating company. Once plated, it will last 10 lifetimes. Call Mike & he'll give you the straight scoop.
Who ever does the work.. be sure to have a good gunsmith go over everything after the process.. Some parts move and need a little tweeking afterwards.. Stu Wright did mine many years ago.. Excellent.. Same for Doug Excellent.. can't speak for any others..
About six months ago Doug Braker did my K-32 and I highly recommend him. Turnaround time was as he estimated, the work was as promised and was beautiful, and he went through the gun and found and fixed a broken part without being asked. His work was terrific and prices very reasonable.