How to mount a public windows 8.1 share in linux

I have a folder shared on a windows 8.1 machine. It is shared with "Everyone" and "Everyone" has "read/write" access. In the security tab of the properties dialog of the folder, again "Everyone" has been given "Full Control". I specifically want this folder to be publically accessible to everyone in the office for reading and writing as a scratch/transfer folder, which should include clients visiting the office, so creating a specific user is not an option.

I have a linux machine, as do some others in the office, and I am having problems mounting the shared folder

root # mount -t cifs -o guest //Beefy/Scratch /mnt/scratch
mount error(13): Permission denied
Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)
root #

/var/log/messages reports

May 31 05:12:28 volundr kernel: CIFS VFS: Error connecting to socket. Aborting operation.
May 31 05:12:28 volundr kernel: CIFS VFS: cifs_mount failed w/return code = -113
May 31 05:12:28 volundr kernel: Status code returned 0xc000006d NT_STATUS_LOGON_FAILURE
May 31 05:12:28 volundr kernel: CIFS VFS: Send error in SessSetup = -13
May 31 05:12:28 volundr kernel: CIFS VFS: cifs_mount failed w/return code = -13

I've also tried using -o sec=ntlm and various other options (ntlmv2, ntlmv2i, ntlmssp, ntlmsspi), -o nounix. If I try with -o guest,sec=ntlmsspi I get

root # mount.cifs -o guest,sec=ntlmsspi //Beefy/scratch /mnt/scratch
mount error(524): Unknown error 524
Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)
root #

And the accompanying log output in /var/log/messages

May 31 05:23:45 volundr kernel: CIFS VFS: Error connecting to socket. Aborting operation.
May 31 05:23:45 volundr kernel: CIFS VFS: cifs_mount failed w/return code = -113
May 31 05:23:46 volundr kernel: CIFS VFS: Server does not support signing!
May 31 05:23:46 volundr kernel: CIFS VFS: cifs_mount failed w/return code = -524

Having seen the "Server does not support signing!" message, it occurs to me that something else relevant might be that I have followed the instructions here on my laptop, just because I'm paranoid. However, the results are the same, even when I have commented out these security settings in /etc/ssh/ssh_config and rebooted.