This post is for people with 1, 2, or all 3 of these situations that apply. 1) limited rolling stock, 2) lacking certain rolling stock, or 3) limited funds. My situation includes all three... so I took a UP coal hopper and since I don't run any coal on my layout, put a styrene roof on it. Then I took an old box car roofwalk, glued that and some sanded teeth from a piece of lego for hatches and voila...instant covered hopper. I followed that with some Testor's brown (which in fact made the roof look weathered) and now my kellogg's plant can get the sugar and corn it needs.