Thanks to Anders Backman's research and efforts, we now know what was going on.   The Tuvans signed contracts with two printing houses, and the contracts weren't just for one issue each.  The Tuvans were in a hurry because the 50th anniversary of their integration into the Soviet Union was fast approaching and they wanted to be again using their own stamps on the anniversary.

He doesn't say so in his catalog, and I can't read the russian contracts which he thoughtfully reproduces, but I suspect the Austrian and Chinese printing houses were to be paid with part of the print run.  Thus even when the Tuvans found they wouldn't be allowed to issue their own stamps, they were still printed.  [That or they had all been prepared while permission was still pending, but that seems very unlikely].

Of these semi-official stamps, all are truely Tuvan-related and are very conservative.   The only exception to this are the provisional overprints on the first triangular set...why were these produced?

In the two years these contracts were in force, they produced two sets we saw before, the overprints on that second set, and then a set for

and individual stamps were made for

These are all described and detailed in Anders Backman's new catalog.   After learning about the reason these issues always seemed different, I created an album for these semi-official issues. These issues are clearly in a different class from the labels that follow...