Hot Rods Help me ID the YOM on the SW oil pressure guage

I found this today at an estate sale. Price was right. I looked online and it says they are date code but I could find any dates. I looked all over online and can't find one exactly like it. 64-65?

 

look for the black stamped numbers/letters. Take the mounting bracket off, to help you see the whole thing.

 

Thanks. I did take off the bracket and there are no numbers.

 

Your guess of mid 60s is correct....

http://www.roadsters.com/sw/

 

Here is a old thread... https://www.jalopyjournal.com/forum/threads/twin-blue-stewart-warner-gauges.543336/

 

With all due respect to Roadsters.com. In that link they are talking about Custom line or commonly known as Greenline gauges, which I believe came out in 1965...but they show what is commonly known as twin blue gauges. Twin Blue gauges from my understanding came out in 1957...I think they were mostly used in marine applications..but obviously some were used in hot rods. So it could be mid 60s made..but could be earlier..as early as 1957.