Formatting in the 7k is not necessary, just safer if using older disks, a pc format will be just as good, make it full rather than quick.
Unfortunately upgrading from 1.3 required that software table 1.4 (disks 3 and 4) went in before disks 1 and 2, the 1.6 update.
I shall mail you 2 disks as an experiment with my own self extractors. Using known good floppies CHECK the download disks and then make and CHECK mine.
Install download disks 3 and 4, then install my 2 disks, then install download disks 1 and 2.
No guarantees, and at your own risk as always mentioned in these threads, but it's worth trying.