I suggest EMSAR as well. They repair ambulance cots, have certified repair personnel, appropriate parts, etc.
(My new boss at work, who has very limited EMS experience, asked me if I did ambulance cot repair or knew someone who did. He needs some cots repaired. I recommended EMSAR, but he said they were too expensive. Uggh, you get what you pay for. Particularly, if I repair the cot and then it fails with a patient, who are they going to sue? At least, with EMSAR, they are the "nationally recognized" cot repair company, and are considered the experts. And they have insurance. Anyway, I told the boss I would not do it.)