Dear Mr. St Claire:
I am in Lake of the Woods, California.
I believe The Secret Galactics was also published under the title Earth Factor X. I did read it (under the latter title) but don't recall much about it except that it was never a favorite. If I remember correctly, one of the characters is a human brain in a "robot suit" or some kind of mobile life support device with arms and claws. At one time I had a copy of all his novels and story collections, but a few got water damaged some years back and I never quite managed to complete the collection again. It runs to over 50 books.
Speaking of van Vogt rarities, Siege of the Unseen, a novelette, was published in the '60s as one half of an Ace Double. As far as I know it's never been republished. I believe it starts with the finding of a dead body which apparently had dropped from a great height. It is subtitled "Evil had a third eye."
Since you're such a fan of Pawns (which I like very much as well), I wonder if you've read the fairly recent Null-A 3. I thought it was very disappointing, really awful, a lot of jumping around the galaxy to no apparent purpose and several characters who just sort of hang around doing nothing until they're needed by the plot. But then it's been more than ten years since I read it. It's the last new work of his that I know of in book form, probably long since out of print (published in the '80s, I'd guess). Also, have you read Van's autobiography, called Reflections of A. E. van Vogt? It came out many years ago and so doesn't say anything about his second marriage, but it's readable and short enough to never get too dull.
Somewhere I read that Van attributed much of his writing skill or style to reading a book by Thomas Uzzell. I found a different book by Uzzell and read quite a lot of it (probably more than 20 years ago), since I was an aspiring writer. It seemed quite good, though perhaps a bit mechanical in its approach. I still recall something about his "wave formula," though I don't know that Van used it much. Of course there was much more to the book than that.
At one time I had started writing reviews of all of Van's books, rereading each and then writing about it, but I think I only got through about four books before going on to something else. Every once in a while I toy with the idea of pursuing that; it would help a lot toward making my van Vogt web page a useful resource.
I think Van's great strengths as a writer were his ready enthusiasm for new theories, a great sense of pacing, and above all a knack for coming up with moments that just stun the reader with their implications. You mentioned the "most intricate plot ever devised to trap one man" from Pawns of Null A, a delicious moment. I remember the scene from World of Null A where Gosseyn is challenged as not being who he claims to be, as well as his claim to be married to Princess Immelda (I think her name was) which also is disputed. And the one that most people know, of course, is the ending of The Weapon Shops of Isher.
He had weaknesses as well. I think he had a less than excellent grasp of basic science and math. For example, in Cosmic Encounter he mentions a temperature of minus 50,000 degrees (which would be much colder than absolute zero, i.e., impossible) and he also mentions plate glass and concrete at a time long before either had been invented. And in Vault of the Beast as I recall the combination to the vault was "the largest prime number," but there is a simple proof that no such largest prime can exist. I don't doubt that other SF authors are guilty of similar goofs.
I've enjoyed writing this, I think I'll post it on my web site. I hope to hear from you again.
Alan