1. Clearly there is some kind of graphic glitch with the Greece artillery. (See picture attached). It doesn't show the picture of the gun in the information window.
2. There is a howitzer in the game wrongly named 105mm howitzer (see picture attached), but it is designated as 122-mm howitzer in the graphics folder of the game, which is correct. There indeed was a 122-mm howitzer in WW1-era Russian army. http://ww1.milua.org/R122hovizer0910.htm and http://en.wikipedia.org/wiki/122_mm_howitzer_M1910/30 If you see these pictures and compare them with the so called 105-mm howitzer, you'll see that they are almost the same. So some corrections are needed here, i suppose.
3. One of the most seen artillery piece in the game is 105-mm gun, but it should be 107-mm gun - see info here http://en.wikipedia.org/wiki/107_mm_gun_M1910/30 Again, the picture from Wikipedia is almost identical with the "105-mm gun". How about renaming it to "107-mm gun"?
4. Last, but not the least, i have seen a super-heavy railroad artillery picture in the game files. Is it present in the game? I haven't seen it yet. Would be cool if we could build and use it.