Elkhorn printed on a vinyl sticker- usualy on left side between door & left tailight on exterior sideing. You 'might' look on inside of cabinet doors. Im unaware on a truck camper any other addtional 'vin' tags, never heard on a truck camper, the frame stamped? Not a vehicle. The number would have been on original paper work. Is the vin or a serial number on the title seller has? Have a aluminum plate stamped at local trophy shop -rivot it to the propane box IF you need it. Otherwise long gone...
To my knowledge Florida does not require a truck camper to be registered or even require title.