Value of 10' x 4' Castrol Lubefast sign.

I found this sign drilled into the joists of the deck of an investment property of mine. It was being used to shield whatever was under the deck from water dripping between the deck boards. As a result there are random screw holes one the sign. I plan on keeping it as you can't find stuff like this anymore and I'm a car guy too.. I'm just curious how much something like this might go for especially due to its size.

Any input is appreciated.