Having recently moved to Colorado I went to the sheriff's department to apply for my CCW. When the lady behind the counter asked for if I had my CO DL I said I didn't and handed her a form the guy at the bank gave me when we opened our accounts with a stamp and his signature and said that would serve as proof of residency.
She asked why I didn't have my CO DL yet and I explained that in Missouri our CCW is tied directly to our DLs and as soon as I got my CO DL my CCW would no longer be valid and I wanted the CO CCW before getting the new DL. She said "Good idea" and as CO law simply states you have to show proof of handgun training within 10 years the certificate from getting my MO CCW was acceptable and she processed the application, took my finger prints, photo and check and I was on my way.
Two weeks later I got the phone call that my permit was ready to be picked up. I took the wife in to apply for hers when I picked up mine and the lady recognized me and as we slid the paperwork through the window she said "same documents as you used, it'll just be a minute".
No muss no fuss, friendly personnel, was a pleasant experience.