VAZ 21031 storyline

I think the readers have probably never heard from the model VAZ 21031.
Heres the thing: VAZ 21031 were only made in 1975, its hard to belive they only made 200 of these. They look the same as every VAZ 2103, no special remark.
But the have a 80 Hp engine 1600cc, the most powerful engine for Ladas at that time.
The cover of the engine is marked yellow, on the engine block also 21031 is inprinted.
The nr 2103(1) is also inprinted on the VIN-plate.
Also the VAZ 21031 uses a different gearbox, its still a 4-speed one but the gears are marked as:

I: 3,242
II: 1,989
III: 1,289
IV: 1,0
R: 3,34

Some reading about it: http://www.ladaklubi.ee/foorum/viewthread.php?tid=14308&page=2
The information is from the book:Võsokoj mõsli plamen(in Russian), written by two former Toglejatti (Lada) factory worker. I have no doubts about the information given in this book.

I dont know how many of these VAZ 21031 are left in Estonia, actually now one knows.