Where to find original aerial photos, where to scan large pics?

I have a number of aerial photos of the farm on which my mother was raised that were taken over the last 50-60 years. I would like to get new prints made as well as have digital copies backed up. They are too large to scan myself, and because they have been displayed they aren't in top form anyway (faded, scratched, etc.). I tried looking up the info found on the back of some of them to see if I could contact any of the businesses that originally sold the photos to my grandparents to see if they have proofs or negatives archived, but either they no longer exist or I just don't have enough info to track them down. Any ideas on how to find the proofs or negatives? The photos were taken in MN about 50 miles southwest of Minneapolis/St.Paul. Where can I take the large photos to have them scanned? Anywhere in Minnesota (twin cities, suburbs) or even the Sioux Falls, SD area would work for taking them to be scanned.