that pretty well dates this sign..
I have a digital collection of Pennzoil adds for every year beginning in 1928 up through the 60's. Some though I cannot officially support their dates as it does not appear on the document. Here is what I have when it comes to dating this sign and the "Bonded" logo. Unfortunately I cannot support the dates of two of these adds any better than what the ebay sellers description said. So read at your own descretion.
FWIW, Within everything I have, the first time I see "Sound you Z" is 1942. And then from 1947 onward, the top slogan is always "Sound you Z". There appears to be a possible overlap of "Bonded" & "Sound your" between 1942-1946.
If anyone has further or more detailed information on this, PLEASE
post it up!!