It's really not "vintage" per-se but thought I'd offer this up here as I've had had it so long with good intentions of doing "something" with it and it never happened.
Free (collect centralish Auckland or cover postage)Cobalt - "Qube 3"
Network Server Appliance.
This is an x86 (AMD K6-2) based one, not MIPS based like the Qube 1 / 2.
When last used it appeared to work 100%, comes with external PSU.
From memory it was the Cobalt badged version, not SUN badged (SUN bought Cobalt while the Qube 3 was in production)
There is lots (almost too much and much of it old) of info. on the net around hacking / updating / getting a more modern Linux build to run on these.
i.e.. Debian http://gnubies.com/linux/cobalt_qube3.html