Towing with a company truck?

Since the original question was, "Are there any laws that would prevent a business owner from using a company truck to tow a personal travel trailer?" I would have to say that he IS the owner of the truck, and can therefore use it for whatever he wants.

That's assuming this is a privately held single-owner company. Partnerships and public corporations are a whole different ball of wax. Your partner may for example not want his half of the truck towing your travel trailer on a personal trip.

Covering up any DOT numbering is a good idea too, and probably the law.