With Samba, a useful adjunct is wsdd.
The only thing it does it to respond to Windows autodiscovery, so you can find the samba shares without having to know either the IP address or hostname of the samba server.
As you stated, user accounts come and go. So it's also worth mentioning that numeric values for user and/or group will be displayed if there are not matching entries in /etc/password and /etc/group.
After all, its only for the benefit of "Meatspace" that the numbers need to be mapped to text.