I have seen one in Maryland that has a great paint job on it honoring the Veterans and such. Its awesome. But as epndydad mentioned, I believe this was built on a commercial truck frame. Basically taking a dump truck, removing the "dump" bed, stretching the truck cab backwards, and then putting a regular super duty dually bed on the frame. Its cool and unique, my only issue is it probably costs about double what you would pay for a super duty on a new lot.
2015 Rockwood Mini Lite 2504S
2015 Ford F150 Ecoboost