I'll have to search for a link, but there's a group dedicated to restoring (stock restoration) these old off road mail trucks. They are located in Wisconsin and they are involved with old thresher groups, etc. I've been busy with some projects so I'll add some updates to this topic once I get more time. But they have something like 30 of these very rare former mail trucks. Its been estimated that there's less than 100 of these left in the country. Some are more desirable than others, etc. Its all cool stuff...