does the 1968 one really exist? or does everyone just have a nickle one?

if someone knows that they acctualy exist how/where can i get one?

A silver 1968 guilder was not reported to exist, not even as a mistake of the mint. Only the 1967 guilder exists in silver and nickel.

This was the outcome of an earlier discussion after reference of the Muntalmanak (leading source on Dutch and colonial coinage) by one of our members:

https://en.numista.com/forum/topic99239.html

So it's a mistake in Numista. The year line needs to be removed. Not sure why it's still there a year later.

 perhaps because the referee did not hear of it because no change request was submitted? 

Or is there a pending request already since many months ?

A referee wouldn't be able to do anything in this situation the moment someone claims to own a year line variant.
Probably just added the comment ‘mistake’ to it.