We use the following with great success.
ACCESS PA 188.8.131.52:210
CHESTERFIELD PL (VA) library.co.chesterfield.va.us:210
FLATIRONS CONSORTIUM (CO) nell.boulder.lib.co.us:210
JEFF COUNTY LIBRARY (CO) 184.108.40.206:210
KANSAS CITY PL kcmo.sirsi.net:2500
LION (CT) catalog.lioninc.org:210
MORE (WI PL CONSORTIUM) www.more.lib.wi.us:210
If you need more settings for any of those, just email me.
If you are looking for UK publications rather than USA, you may be able
to sign up for Z39.50 access to The British Library. Here's a contact.
When we signed up, you needed to contact them to get approval and they
would send the appropriate Z39.50 settings to you.
**Online Systems Analyst**