Yes, repopping the C knuckle is a possibility. If the raw forging is made "smartly" then the one forging can be machined to fit all A, B, E cars. It will also fit most C body cars as well as all FMJ cars.

The suspension guys would need to sort out the effects of the taller knuckle. Different brakes can be made to fit by machining the spindle for a different combination of wheel bearings. The lower ball joint bolt spacing is different between the ABE and C body cars but that is an easy drill pattern change.

There is a pretty good product hiding in the details if a person has the resources to do the work. A fitment matrix needs to be filled out and then the marketing guys can develop some sales forecasts. That will tell you if you can afford the $100K+ for a high quality forging die.