OK....I've got the printer off my Linksys Print Server into the correct Workgroup (and set to a fixed IP address, per the suggested conventions).
Each of the various users I have created on the Vista machine can access this printer.
BUT......
When I "shutdown" Vista and then log in, that default printer is now Offline, and can't be reset to be Online. If I create AddNewPrinter and give it another name, all is well. When I "shutdown" and restart, both printer icons show "offline".
There must be some other magic I need to tweak.

The "tweak" needed is as follows (from information I found on other threads):
First, ensure that the PrintServer is in the same Domain as all the devices on the LAN. Access the PrintServer admin page to confirm the domain name.
Then, for each user configured on the Vista desktop, one must associate the PrintServer printer port to a "persistent" network connection.
Launch a DOS command window (start/run/cmd)
If desired, enter
net help
to see the commands available
Enter
net use LPT1 \\[printservername]\P1 /persistent:yes
where [printservername] is the name of the PrintServer device.
This mapping of LPT1 to the PrintServer port as a persistent connection must be done for EACH user defined for the Vista desktop.
((WHY one needs to get down to the "DOS level" to establish this is beyond me. But, it works, and that's all I need to know.))
To verify, exit CMD window and step through each user on Vista to confirm that the printer is available to each user and works correctly.