my '50 has ths valve, there is a brass nipple (about 3" long) between it & the gas tank, the valve is made like a cross, the top goes up to the tank, bottom has a cleanout plug, the shutoff is on one side, rubber fuel line connects the other side to the metal fuel line.

here's a pic, http://memimage.cardomain.com/ride_images/2/2877/4121/19692060138_large.jpg