ReadyNAS 4 -> 6 OS upgrade addon files not available?

I have two of the 3200 v1 units running in my environment and I found out that there was a means by which I could upgrade to OS 6 from 4.2.x. The links to the R4toR6_Prep_addon.bin and R4toR6_latest-beta.bin are no good no matter where I try. It seems that NetGear has decided that redirecting them to the ReadyNAS landing page is a better idea. There isn't even a "You're late to the party" notification saying that the files are no longer offered from the site. While I am well aware that NG doesn't support this upgrade, I would still like to join the many folks who have done so for the better OS.

Is there anyone who is able to point me to a download for the addon and the 4 -> 6 bin files?

Thanks