Hi gp:
These knives have been discussed on this Forum previously. There is also a nice historical three-part description online, starting
here, that traces the history, manufacture, and cultural significance of these knives.
What you have is a bone-handled version of a common form of Cretan knife made for those who travel. The modern Greek inscription and a rough outline of the island inscribed on the blade is typical. The 1961 date is probably an accurate reflection of when it was made.
I have a similar knife that was also dated 1961 and was discussed on the old UBB Forum (now no longer available). I will try to find the old pictures and post them.
Ian.