This is the SCO UNIX DevSys Maintenance Supplement 4.2, dumped by plamen
unfortunately in tap2 format (in "sco.7z") archive.

I used script from https://github.com/wfjm/w11/blob/master/tools/bin/tap2file
to extract files in the tape and them glueing them together into native SCO
tape format.

In order to install the DevSys through a (virtual) CD-ROM drive, insert the
"diskette_cdrom.img" floppy instead of "diskette.img", and tape image into
the CD-ROM drive. Then run "custom" as usual.

Serial for the bundle can be generated through the "brandy" tool with adb
as "product code".