With the 4-9-4 blocks, if you set the "Left" or "Right" skin, it shows up as being in its opposite direction (also happens for their White variants). I'm guessing this block model's UV mapping was flipped?
Something similar also happens with 4-9-5. If I place a "Left" or "Right" skin, it looks correct when up close:

But if you get back enough, the bottom-left sign of the block reverses direction while the others stay the same:

Also a smaller thing - when you click to skin any 4-9 series block and the dialog comes up, the choice in the dialog is always "Down" (the first entry) regardless of whichever skin was picked beforehand. However if "Default" was the block's skin beforehand, it correctly highlights that choice in the dialog.
And if "Down" is the choice in the dialog when the block's original skin wasn't "Down", clicking this button doesn't make any change to the skin (you can work around this by choosing a skin not highlighted, then choosing the intended one).
Generally this extends to block skinning with the other set of signs, and the behaviour of which sign gets selected in the dialog is more unexpected.
Thanks!
PS. My shader quality is set to Fast, textures are Medium and I'm using HD textures if that affects anything.