good on you for having a go!
i'd be replacing that pvc elbow ASAP.
billsy spec piping! theoretically it should be good, but i don't know how long they go with the clamping forces.
also, as stated, try flipping the core, and you may be able to put the foggies back in!
We used class-18 pressure pipe for the elbow, so it's damn strong! I'd say a wall thickness of 5-6mm, and you'll never crack a tube like that under compression... so I don't see any real need to replace it! We ground a few grooves into the ends with the bench grinder and roughed up the surface with some very coarse sandpaper (i.e. about 40-grit) to make sure the joiners didn't blow off, so there really shouldn't be too many issues.
As for flipping the core, simply not gonna happen if you want to keep ANY resemblance of a crash bar... if you used a shorter core (as in width, not height) and used custom end-tanks (such as an Evo one maybe) you could possibly come up similar to the cold side and keep the foggies, but that would be a 100% custom setup, not using this kit. The way the kit fits up there is NO WAY you can keep the foggies - simply impossible.
I was simply blown away at how little room there was once the bumper was removed - I mean I've got an R33 Skyline and fitting the cooler to that (and it was a MUCH bigger one as well) was a piece of cake compared to this. Did the whole lot in a few hours, including cutting out a chunk of the crash bar and the plastic bumper. The other thing is that we didn't want to cut any more out of the crash bar than we absolutely needed to - this way we were able to only cut the underside and keep the full front face and at worst a small amount of rolled edge along the bottom for strength.