I was looking through an old August 1962 MR issue (page 10) and I saw an article on the "new" Model Die Casting HO covered hopper. It's hard to beleive this is almost 50 years ago! The article mentioned that this was the first authentic looking covered hopper - "at last". Molded on grab irons, ladders, horn-hook couplers, and all.
Here are three that I kit bashed with wire grab irons, and ladders, Square instead of round hatches, cut out panels on the sides and Kadee trucks and couplers. I think I made these around 1970 or so.
I remember ones like this on the SP San Ramon branch back in 1962 - and I really wanted them. If you wanted those features back then you could either buy expensive brass cars, scratchbuild or kit bash.
Now Intermountain makes ones like this for around $30.00 that are even better.