Not sure if it will come off or not. I didn't want to ruin anything so I'm leaving it as is. This is a double sided metal sign made by Stout. I'm pretty sure you won't find a sign with holder complete this in this condition. See pictures for more description.
The item "RARE Vintage PETER MAX Psychedelic 2 Sided OPEN 7-UP Soda Advertising Metal Sign" is in sale since Tuesday, March 24, 2020. This item is in the category "Collectibles\Advertising\Merchandise & Memorabilia\Signs\Original\1930-69". The seller is "allysattic21" and is located in Dimondale, Michigan. This item can be shipped worldwide.