Check out their new Ciabatta. I'm not entirely sure how it works or how you operate it, but it's aparently a new type of "assisted" knife that sidesteps the switchblade laws in most states. However, this is more a Godson sized knife, and doesn't have any inserts.
As for a Godfather itself,
here is a discussion which would suggest that if you remove the spring, it's no longer a switchblade. However, I would tighten the pivot enough so that you have to physically move the blade (not just gravity or inertia) to open it, although even then it wouldn't be much different than flicking open any other knife.
But a Godfather? Why do you want the knife? Did you actually get to handle one? The Godfather is more of a grown-up's toy than a knife for every day use. The hollow ground blade is very thin and stabby, and I could see the tip snapping off with anything but the most conservative useage. If you just want the knife as a desktop toy, keep it as an automatic. It's not illegal to own a switchblade within your own home. Just don't carry it.
If you want a knife to carry and use, get a Godson instead of the Godfather. They have the same style blade, but the Godson is flat ground instead of hollow ground, and is much stronger because of it. You can get the same style (with maple burl inserts) in a Godson that you like about the Godfather you're looking at. The only problem I can see with using a Godson with the spring removed (the Godfather would have the same problem too) is that in the closed position, there's not much blade to grab onto to open it. Maybe you have a machinest friend who could put a nail-nick in for you.