So the last few days I've been working to get the front clip squared up. I didn't like the gaps from the fenders and hood or that the front clip just didn't look right. I'm glad I kept the original front end as that was very helpful along with the Mach 1 to get the measurements I needed.
Overall, I'm really happy with the fender/hood/cowl gaps. Even in this rough mockup, I like the results. I'm actually quite surprised how tight the gaps are.
The fender apron brackets were a pain. I even tried using an original one, but that fit worse than the new ones. The metal is noticeably thicker on the original versus the aftermarket bracket FYI. I don't know how that will affect strength, but there is a significant difference in metal thickness.
I ended up having to buy a second passenger side inner fender apron because the Canadian one I bought fit terribly (I didn't read the description on NPD's website, and it does mention the fit). So far they both seem to fit terribly, but the import brand (which is less money by the way) required less cutting away of material to get the measurements I needed. Neither of them hug the contours of the firewall precisely, but they will have to do for now.
I tried mocking up the new fenders I bought recently, but they were not cooperating. I tried installing the passenger side one on the Mach 1 too and it just didn't fit right. The original fenders just fit better. They don't fit the doors that well. I wonder if I should try installing the original doors now too and see how they go together.
The front bolt holes on the aftermarket fenders also do not line up with the core support at all. I don't like that. The original ones like up well enough. I'll try installing the new headlight buckets and see how those fit next.
The hood is just laying there, no hinges installed, but looks nice and straight
The front end is about 1/16th - 1/8" off from being perfectly square. I just can't get it closer than that. It'll have to do.