NEC NEAX IVS2 PBX with NEAXMAIL AD-8 - hard drive clone issues

[keith at saracom.com]

Hi Everyone, 

Not a classic computer but has a 386 embedded in it for the voice mail. 
I rescued it from work.  We had it rung for 20 years straight.  The
voice mail (AD-8) is basically a 386 running MS-DOS 6.22.  So my concern
is the hard drive.  It is the original 2.5 inch IDE IBM Travelstar 6 GB
drive.  It has bee running for 20 years except for a handful of extended
power outages.  Hence while it is working now,  I don't have too much
hope for the future.  The PBX had its on battery backup and also was
always connected to a UPS.  I have tried to copy it to an industrial CF
card but no luck.  I have used Rufus, Active Disk Image, and Macrium
Reflect. 

I don't have my older PCs up and running at the moment, hence I have
been trying with a Window's 10 machine and USB adapters to no avail. 
Since the voicemail card is running headless, I can't see the error
messages.  There is a serial port but but I have figured out the
settings yet. 

Any suggestions?  Do I need to get a DOS machine running to do this?  

And yes,  I really don't need the voicemail working,  nor do I need a
PBX in my house but why not?