It would look super-bitchin' but man, what a lot of work. I, like Dave, am no engineer, but I would think that welding the tubes in would bring back the structural integrity. I think the only way it would look right is to chamfer the ends of the tubes (like sharpening a pencil) and just fill the crevice with weld so you could grind the surface smooth. I don't know if this lends any credibility, but I wouldn't hesitate doing it to my rod if I had the time.

On a separate note, and this is just my opinion, the radiator shell should have the same slant as the firewall when the car is viewed from the side. To me, it looks dorky to have the shell sitting at a different angle. There is another benefit to doing it that way. When you add hood sides (and I think you should on a Lakes car), the angles will all be square.