Shortly after I bought my Ultra Crimson Carry II a couple of years ago, I sent it to Kimber for them to put night sights on it. When they received it, they gave me a call to confirm what I wanted. Then they mentioned they saw a little rust in the barrel (I was more than a little surprised by that), and gave me some advice on cleaning it. I talked with them a little longer about the gun, and that was that.
So, based on my limited experience, they do have a true custom shop and they handle repairs, etc., themselves. And they were very knowledgeable and seemed anxious to help.