That three-port Buick reminds me of the one my grandpa was driving when he died in 1955. As a small boy, I used to marvel at the radio antenna located at the top of the windshield. You could turn the knob inside and watch the antenna rotate 360 degrees on its axis, for whatever reason one might want to rotate the antenna. Only Buick knows why a driver would want to. If you had the antenna fully extended for good reception, it would hit the cowl when you rotated it down. I never told grandpa how I found that out.
I see somebody made an RV out of his. I bet it knocked a MPG or two from the nine it usually makes with that big ole straight-8.
In some countries such as Uruguay and Chile, importing cars as a chassis-cab for the fitment of locally-made rear bodies qualified for lower import duties at least until the '60s or '70s.