Walthers HO Cornerstone. Walthers N Cornerstone. Walthers Glacier Gravel. Walthers Background Bldg. It looks great as part of a stone quarry, alongside the New River Mining Co. (933-3017) and Coal Flood Loader (933-3051) in a mine, or as part of a slag recovery operation down from the steel mill buildings of The Works. | eBay!