Hi Bulldog and MGM. The best source for info to begin with for the MGB front sway bar is Moss Motors, then e-bay. Lot's of info out there.
Moss Motors 7/8" front sway bar for all MGB's is the same for 72-80 and part number is 454-955.
Lots of used stuff on e-bay.
Here are a couple of pics.
Cheers
Greg