Difficult to accurately date the blanchards, they run the same patterns for many years.
But this one is quite new (relatively !), could be 25 years old, could be 50. Its the last version of the old pattern, before they switched to the newer lever style.
Not sure if the blade is the original, looks very new, but that doesn't really matter.
its the 15cm version, which is good news.
Value, 150 Euro + in Europe.
to sharpen it, only do the inside of the blade (side with the blanchard mark), you want a very small angle so should expect to see a taper from about 10 - 15mm out from the edge.