Trying to recover Smithy 12x40 Mill after motherboard death

I have a 2013 era Smithy CNC Mill.  The mother board died. I've got the system disk so I have the last working configuration.

I've purchased a new mother board and disk.  I've installed the latest LinuxCNC distro on the new disk.
I copied the "configs"  folder over to the new system and linux CNC sees them.  I need to get the rest of the foundation put in place.

I need to load the drivers and firmware for the Mesa boards.  The system uses a Mesa 5I20 board, with a 7I47 board and 7I37-TA board.

I have tried finding the hostmot2 driver using apt but have failed.  I suspect I need to add a repository but I don't know which one.  If you could point me to a thread or article that gives me the background I'll try it from there.

Best Regards,
Evan R.

If you have the old hard drive, its not a bad idea to copy the original
/lib/firmware/5i20/ contents to the new system as its possible the firmware
used on the 5I20 is custom for the Smithy (It could be recreated if need be
but copying the old firmware file would avoid that)