Hi
There is not much hope to pin the date much further down than indicated by Steve.
Check the Jezler Website, their catalogue:
http://www.jezler.ch/pdf/Jezler_Besteck_RZ.pdf
The pattern of your items is "Pricess". This pattern was introduced in 1938. Jezler stopped producing items in the "800" silver alloy around 1990 and moved to the "925" alloy exclusively. So this are the absolute boundries for dating, 1938-1990. Jezler had in the late 1800 and early 1900 a variety of mark pattern which helped dating the item. But then around 1920 they moved to the standard marks "Jezler" or the crest, which remained unchanged. So the marking is of no help. I agree with Steve the items look very 1950ies. Allow me to make the educated guess "between 1950 and 1970, with a possibility in the 1940ies".
Regards, Jörg