Hista will tell you nothing apart from Unix boot and base system loaded. DSSM is not going to help here.
You didn't need to give the ADP a soft restart, you could have rebooted the Unixware only, using UBA. But it doesn't matter, it hasn't recovered correctly and so it probably would have died either way.
You need to connect with command line to look further. V5 was SSH not telnet I think so putty will work fine. You should putty to the IP address of the Assistant and try and login with your engr login. Once logged in, you can make the cs_control (you could have done this to start with but too late now) but it won't fix your login issue.
The login issue will be something else but difficult to know what. The Assistant is running but one of the applications is not. I'd first check that you don't have any full partitions, use "df -kh".
If you don't have putty, from comwin you can use "sta-uw7;" and login from there, I think that's still there in V5. If not, get putty.
You can make a manual reinstallation from command line which would solve the problem but you'd need to reconfig IP, gateway, etc afterwards as it would install on the 192.0.2.5 default. That's assuming the install files are still there and I'm sure they will be. Reinstall would be a reliable way to solve it, takes about an hour, no telephony downtime. If you have regular HBR backups you can restore afterwards but no need unless you had any personal data in the CM, room, location, etc. If not, I'd just reinstall and correct IP config.
Check for full partitions first. If there are any, clean up and reboot (reboot/init 6 will work fine).