What does 191767 mean in "Paper, Cardboard for Set 4336 #1, Scala Cat (191767)"
My guess would be that it is the LEGO element ID (6-7 digits as far as my observation goes). This is different from the item number which is shown on the bricks or on BrickLink. The item number usually contains (or is equal to) the design number.

Example: I have a 2x6 plate in tan. This shows the number 3795. As this is a common piece I looked it up on the LEGO website (search by design number) and this reveals that the element ID (which also contains color information) is 4113993. Some element IDs contain the design number as well, e.g. 379501 is the very same plate in white.

Unfortunately the piece in question seems to be rather old, so I could not find any information about it online. (And to find element IDs is a challange by itself as they seem to be "LEGO internal".)