Does it meet the health codes for your area? Is that a gravity water system, looks like you fill the tank on the roof, where does it drain? Does the steam table work properly?
If you knnow the last name of the business that operated out of it, see if you can find anything related to health permits issued under that business name. If it was ok once it should be ok now unless they have changed the laws.
KCBS CBJ 9831
Large Spicewine, Backwoods Smoker (Party), WSM, Oklahoma Joe's Offset, Wood Fired Oven