Missing Printer

My antique RPS thermal printer that I use for development disappeared from the network today.  Last night I was sending it test jobs trying to get a new label to format correctly and this morning when I called it

lpr -P Zebra1 testlabel.txt

the server replied that the device was not accepting jobs. 
The printers are all at workstations and shared back to the server so the server can send jobs to them.  I’ve never had a problem before, and the only error message in CUPS error_log (yes, lets start a new naming system just for CUPS logs) was that it couldn’t find the server name.  The CUPS web page showed the printer still listed, but the location and description were “Unknown” and the URI was set to file:/dev/null.  I modified the printer settings and pointed it back to my workstation, and after some trouble (Firefox, HTTPS, and CUPS don’t mix) I got it running again.  Later this afternoon, though, the printer reappeared.  Now I’ve got it listed twice.
The only thing I can come up with is the broadcast of available printers from my workstation got lost somewhere.  I must have let CUPS add the printer on it’s own via Show printers shared by other systems.   From now on I’m going to manually add printers instead of depending on local browsing to get them to show up.  In fact, I may just disable browsing altogether.