As Elliot's Barbecue in Charlotte is the western-most outpost of Eastern-NC-style barbecue, Shell's Bar-B-Q in Hickory N.C. is the northern-most outpost of South Carolina-style mustard-base sauce pork barbecue I've run across.
Made with just enough mustard in the otherwise plain Eastern-NC-style vinegar sauce to give it a very pleasantly surprising both initial taste and mildly pungent mustard aftertaste, it's subtle enough to where if you had either standard old Texas Pete or their Western-NC-style ketchup-based vinegar sauce to it, the mustard base flavor quickly and quietly goes away or at least fades into the background so you can taste either the 'Pete or the Lexington-style house sauce instead.
The chop is fine but not to the point of mush, a consistently fork-size chop that sits well on the tongue and the barbecue itself is clean, though they do deliberately include bits of cooked pork rind/skin in with the mix, something I don't particularly care for but many people like.
One unusual side item they have that I've never encountered before are "Tater Tots", as in the kind of processed potato "nuggests" you'll find in the frozen foods section of your grocery store, and they cook them perfectly. In fact, each time I've eaten at Shell's that's the only side I order other than their better than average hush puppies, they cooking them so perfectly if they are initially store-bought and not homemade that I could make a meal off of them alone if their 'cue wasn't so excellent. This being the western part of North Carolina just at the foothills of the Blue Ridge Mountains and Blue Ridge Parkway, it's not unusual to find Tater Tots and "liver mush" (don't ask if you really don't want to know) and other otherwise home-style exotic items on any local menu. Oh, and even if you love Tater Tots, you simply must try their cheese fries also, they are truly excellent.
Located in a reasonably authentic shiny-diner just a few miles off of Interstate 40 in Hickory (Hickory straddles I-40) and is fairly easy to both initially find and get back to the highway from, it does tend to get a little crowded and stuffy inside at times especially at nighttime dinner time but the atmosphere for a barbecue restaurant is unique as far as my own experiences go and you'll find even more families there than even a typical barbecue joint which are always very family-friendly, kids just love the atmosphere. Lunch is usually more drive-through than sit-in and their service for both drive-through and dine-in is as fast as it gets and almost never is any mistake made on your order, quick, fast and correct.