I bought mine used through an online sight (hmmmbay). I did have to call Walter and people at another sight gave me his number. You are right in that there is some covert operation going on. It seems no one will publish his number but they are always happy to email it to you. I have it if you want it.
So, Walter does not have a web site and the last time I saw any advertising from him was on the back of a Rufus Reid Book from the early 80's!!!
No, web site, no advertising!!! Only word of mouth. He makes all his amps by hand and there is a waiting list (or that is the rumour). I had to try many times to get him to call me back (had to leave voice messages), but when I did get through to him, he was very helpful and friendly and gave me the time of day even though my amp is second hand!
His amps are expensive, but you get an incrdible amp in a very small package- I carry mine in my backpack along with other gear. I do think they are over-hyped by those that own them, but I feel that way about owners of EVERY high end manufacture from Alembic to Zon!
I would love to A-B the following 4 set ups which I consider (IMO) the best, albeit all expensive options:
1) Walter Woods into a Berg cab or whatever
2) Bergantino IP series combo (any one will do)
3) Sadowsky SA200 into a Sadowsky cab or Berg cab
4) Alembic F1X into a Crest or QSC amp into a berg or whatever cab!!!!