Someone asked for mercator's home adr in email a few weeks ago (but your email is bouncing). It is buried in Compaq's research center site under the projects menu:
I hadn't been there in awhile and just found a fact I've never seen before: Alta is now using the mercator software [research.digital.com] (agent name still scooter though). Alta 3 - Mercator [doc.altavista.com].