Did we both go to the same site? lol. If it wasn't for it's top heaviness, I think it would do great in battle. Your turn.
That makes it so easy ... just go to the site, click on the country and scroll down. Starts with 'C'.
I'm afraid I can't find a reference to a tank called "SIj-T3D" on the Web. Can you provide a link? In any case, your first guess was VERY, VERY close. This was a tank that was accepted by the army, though only 50 units were produced - unlike the more popular 35 and 38.
The czech tanks are a mess to identify, not only were the designs produced a bit all over Europe but a number of very similar variants of the two basic designs existed Lt zv 34
Tired Old Soldier is correct. This was a design that preceded the Lahky Tank LT vz. 35 by one year, and saw limited production - but it was accepted into the Czech Army before it was replaced by the later 35 and 38 models.
I had noted the name but left it as "praga" alone would not be an acceptable answer. I admit I was lazy, I'm out of good pictures. I believe the official name is Panzerwagen Pzw.39 (sounds German but so does the language spoken some areas of Switzerland) but it essentially is a "Swiss praga". Over to you but don't pick something from "that site" too.
the first two look like shermans.....the last one looks like it has its turret turned around.....so i cant make a definite guess....
The first one is a dummy tank, I think. I don't know what is special about the second one, though the tracks look different from the standard Sherman ones.