Wikipedia mentions only TCP port 445 (while as far as I can remember ports 137-139 used to be used actively by Windows file sharing).
If I map the 445th TCP port on gateway host "A" to a 445th TCP port of SAMBA server host "B", will Windows XP client host "C" be able to access shared folders on "B" by typing "\ipAddresOfHostA\" in his address bar while being connected with "A" with OpenVPN TCP/IP tunnelling?
PS: No broadcasting and discovery features needed - clients will always explicitly specify UNC address to access the resource.