Can/should lower control arms be modified to accept sway bar?

Welding the clips on for the factory sway bar isn't a big deal. Reproductions of both types have been offered . I don't recall where.
Aftermarket bars use clips added at the shock bolt. Lots of users weld those also.

Hotchkiss offers reproduction tabs for the 73-76 A Body, 70-72 B Body, & 70-74 E Body cars, which are all the same.
They also have reproduction tabs for the 66-69 B Body cars.
They do not have anything for the 65-72 A Body tabs.