I have not held the sign in question,as such I can't say if it is original or not.
But, such signage was in use in the mid 1950s until the mid 1970s... I took a few such signs off of Stations that were being "removed" and/or "refurbished" in the 60s and 70s...
Since it is Oilzum, one is assured that it has been "popped". Here is one of the "new 'popped versions". And they come already distressed.
# 380687214030
An original (IMO), mid 1950s- mid 1970s; "Dealer Sign" that went unsold on ebay:
1956 image of Oilzum Wall advertising:
