There was a recall back in the '90s I had 2 that were replaced. Was hard to tell the difference even harder to see in your photos.
One thing I rembember was a large weld dot on one side of the new one.
I threw out my stem last year.
Even if this one is post recall if it's been ridden a lot it is time to replace it.
These parts all have short lives and aren't meant to be used forever.
Then again it's your collarbone.
Well it does have a big weld dot on the left side, and one on the underside of the bar clamp. That makes me feel better at least. I really don't sprint on my vintage bikes. I do more high speed cruising. I just didn't want it to let go on me at 25mph.,,,,BD