What about rwhois?

Should support the refer attribute of RIPE-189 objects.

I need a procedure for looking up an IPv6 address in a list of prefixes.
Will anybody contribute it?

Add Exodus rwhois server (e.g. 216.35.0.0/16).
Add rwhois.verio.net:4321 (e.g. 192.204.0.0/16).