This is no longer the case, but we used to have a Delta Truck Body plant in the next town over. When they put their body on a truck, they put their own mud flaps on, with their logo, and took off whatever the truck had on it when it came in. I had a friend who worked there part time. He was able to get me a brand new set of flaps with the name of some truck stop in Nebraska, I believe. I have them on my '47. They look great, and didn't cost me anything!
I guess my point is, if you have a place like that near you, check with them.