Wow this brings me back 11 years when I bought mine and had to put a new radiator in right after I bought it - I broke my shroud too! Mine broke in only one spot and it was a fairly clean break but it was at the top just to the pass side in a noticeable location. Long story short: I converted it into a two-piece shroud that I still have today. After it broke, it came out easy and I made a clean cut at the bottom to get it into two pieces. At the time, I worked at a company that had an aluminum fab shop as part of its business. I talked a couple of the fab guys to help me out with some slice plates that allowed me to bolt the two pieces back together once they were in the proper locations. I painted the pieces flat black and they almost look like GM made it that way, but not quite. But the ease factor in getting that thing out now almost makes it worth it. Not sure you'd be able to do that with the shroud in three pieces - might be a little too hokey. But just thought I'd give you that option.
Regarding a one-piece replacement: have you scoured e-bay? Craigslist? Do you have a classic cars wrecking yard in your area? There's one here and they have about five or so C3's, but parts aren't a lot cheaper than new ones from the vendors, it seems.
Regarding your radiator hose saw-thru issue: I've had that before, too, and I'm guessing it's your alternator belt. That top hose has to be rotated to the perfect position for it to not rub, get kinked or squished on something. Try some different rotations to see if the rubbing stops. The hoses you buy from parts stores are often not molded exactly like the original, too, so that could be part of the problem.
Good luck!
______________
1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
