I don't know how often you've ever done this (if at all), but every once in a while I'll do a search for local stuff on eBay. Sometimes some very unique items are for sale. Other times there's not a lot. But every time I've ever done a search, I've come across a ton of old postcards. Some of them are pretty old, and some of them are pretty interesting.
Take a look at some of the vintage Sedalia postcards that are now for sale on eBay. You'll probably recognize some of these locations, which haven't changed a lot in over 100 years! Other locations might not be quite as recognizable.