ReadyNAS Tech support mode to copy files to USB Drive or Network?

I hope someone can help, or point me in the right direction,  I have a Pro 6 running OS6, been fine for years,  it locked up, I rebooted it, and this time it loaded in to Safe mode,  after a lot of googleling, it seems the /dev/md0 is corrupt, corrupt leaf.

Its not recoverable, well, not for me anyway :-)

Tried a OS Resintall but it just hangs on FS Check

I can get in to Tech Support Mode, and can mount my drives thanks to the other posts

But what I can not seem to do is mount a USB drive, i just get invalid argument.

the NAS is 6 x 4TB Drives, and I would like to copy about 100GB off it, nothing major, I do have backups,

At first this started out as "can I do it", having battled so far, and over comming issues im just stumped but this, it seems no one else if having issues mounting a drive.

I can mount a 30GB FAT32 drive(single partition on a 2TB Drive) ok, but long file names are not kept, and that kinda messes thing up.

Is it possible to copy files over the network in anyway  or mount the drives in NTFS at all?

Thanks