I am downloading ftk3252456602304584541.pkg
I'm not sure what that will give me. Is it helpful?
From where did you get it? If not directly from Apple, I strongly urge you to trash it.
If, on the other hand, you got it directly from Apple, you'll have to do your own research; you can start with ftk3252456602304584541.pkg - Google Search
. (It looks like you'll have to manipulate your download before you'll be able to use it as an installer.)
I've never run across your situation before, and I can't offer any more advice that I'd feel comfortable giving you.
(The App Store is still down? You've waited this long to take the plunge, why not just wait out the outage and be certain of what you've got?)