Finder identifies smb:// as a local filesystem and refuses to mount port 445 even if you've set up an SSH tunnel using -L 445:localhost:445
The solution is to alias your lo0 interface to and Finder doesn't see this as a local address.
sudo ifconfig lo0 alias up
Create the ssh tunnel and map to your Samba / CIFS server
ssh user@remote -L
Now you can open the share in Finder