Are you sure they ONLY made 550, 383-4 speeds?
The reason I ask is because it seemed like they were everywhere back in 65. My Brother had a red one (very similar to a XF red), and the neighbor across the the street had a twin to yours.
I think 65 was one of the best looking "B-Bodies" Plymouth ever built.
I'm kind of partial the the S/S scoop on your hood too.