I agree completely, Kevin Ayers is fantastic, and by dint of his being part of The Wilde Flowers should be included. But, to fair, Syd Barrett is not included in the Archives either (that I can tell), and he is, rightfully or not, the artist to whom Mr. Ayers is most often compared. This has always puzzled me. Actually, what puzzlez me more is the fact that Barrett is so venerated and Ayers is virtually (or so it has been my experience) unknown, at least in the U.S.
This is not to say that I don't respect Barrett, I just don't worship at his feet. I think Ayers is FAR more talented and worthy of respect, acknowledgement, whatever. Just my opinion.
The Confessions of Dr Dream was his first album for the Island label, so that probably has something to do with its lack of availability.
Cheers!