Yes, it is Dennis Brain. For my money the greatest horn player of all time. I had a scholarship to play the horn in college and performed all 4 of the Mozart concertos. Not As technically technically demanding as some, but easily my favorite.
I was a horn player in high school. This was the only concerto of Mozart’s that I could come anywhere close to playing. Simple melody and not a lot of embellishment.
I was first chair until my Senior year when some sophomore who could play circles around me knocked me down to 2nd chair. 2nd Chair parts for horn suck. I asked the director to kick me down to 3rd chair. The parts for first and third are pretty much the same. You probably know that.
The Sophomore who beat me out ended up playing in the Munich Symphony Orchestra.