Tty port

Is there an easy to see which /dev/tty a printer is on on SCO Unix 3.2.4.2?

Two ways.

Look on the back of the computer; COM1 and COM2 are usually marked. If you have a multiport serial card, then the pigtails are usually marked.
Logically:
Start 'sysadmsh' and go to the printers sub menu and view the details for the particular printer.

lpstat -t

should also show the printer details as well as outstanding print jobs.