Jim,
While I don't have an answer to the specific problem at hand for you, I know a used dealer of DRV products that has installed the Sears toploader in some of the units they buy and then resell. They are a really nice couple, so you might try contacting them via their website and see if they can answer your questions.
They are out of Elk City, OK and their business is called Rolling Retreats. Here is a link to their website.
http://www.rollingretreats.com/
Terry