That looks like a product called " Mileage Minder". It is a combination fuel filter with sediment bowl and non adjustable fuel pressure regulator. That is the correct placement for that accessory. Mileage minders were an accessory some garages would install for customers to help increase fuel economy. The main benefit was that you could see the fuel quality before the carburetor, and clean the bowl of water and sediment. When you saw water or dirt in the bowl, it indicated there was dirty fuel in the system. Then it was time to clean the fuel tank and carburetor. I also installed some Mileage Minders in the 60's on some AMC vehicles.
