So, Man of Gold and Flamesong are (if not actually in print) available and can even (if one is lucky) find them in used bookstores. ($3-4 on ebay)
Lords of Tsámra
Prince of Skulls
A Death of Kings
...are all nearly impossible to find, or priced ridiculously on ebay, etc.
Clearly, the text of these books is completed and even already edited.
The MAR Barker Estate (likely his wife) owns the licenses to these books, I presume?
There was a website, I've forgotten which, that claimed they were 'working on cleaning these up for print' but I can't imagine what was actually NEEDED. Even if they had to be retyped from manuscript into data form, that's a matter of days or weeks, not years.
Mitlanyál, Vol. 1: The Gods of Stability (Tekumel) is selling for $175 on Amazon.
A Death Of Kings is selling for $149.
It seems obvious that there's SOME demand for these books, and it seems also obvious that there's little work required to get them to print.
With vanity publishers, you don't need a substantial number of books to print a run any more - heck, they'd do it for 10 books.
So any idea what's the hold up?
I'd CHEERFULLY volunteer my time to clean up and convert them if needed, under NDA contract to make $0. I'd even put them in touch with printers I know.