Mont,

Since the sunshine kit is hard to find, you can also use an Intermountain kit and Pierre Oliver's excellent roof and hatch detail mini-kit.  See:

http://www.yarmouthmodelworks.com/index.php/ResinModelKits/Index

Scroll about 3/4 of the way down the page.

There is a decal set available through Tichy:

https://www.tichytraingroup.com/Shop/tabid/91/c/hopper-covered/p/10263-monon-covered-hopper-decal/Default.aspx

There was also a set done by Champ, HC-71.

Not bad for a lot of 100 cars!

MIke Aufderheide