For food, farmer's markets usually work well; if you can't find one locally whose hours and sellers sync up with your food needs, look at all your local grocers - there should be at least one who gets a lot of local goods, and puts signs on the shelves proclaiming this.
Note that farmers markets don't guarantee that the produce is actually local. Realistically you'd need to camp out early enough to catch them shipping it on site to figure out where it's actually from.
Usually its obvious that the heirloom produce they are selling would be impossible to ship long distances. an heirloom tomato is amazingly fragile compared to a roma bred for shipping.
Go to the "bad side of the tracks" and walk in. All towns have a bunch of generic machine shops that can manufacture. Look for welders, machinists, sheet metal and that type of thing in the name. Then walk into the office.
Note that few of them will do the design/engineering work for you. But if you have a "blueprint" they will build it. Be prepared to pay - they are all making good wages for your city not third world step above slave wages.
I was thinking more finished goods made locally, rather than custom-made. I’m guessing the coverage will be pretty meager, though. But good advice for the next time I want something a bit more unique, thanks!