Question on the 1650 model (whirlwind)

[not-too-sharp]

1. What was the first year they were introduced?
2. What blade steels have been used for this model?
Thanks for any help in advance. -Andrew
EDIT to title: model 1560

 

[kershawguy]

I am missing a few catalogs in the years that this would have first come out, so I have to guess and say around 1999 or 2000. It was first made with 440A and then of course went to Sandvik 13C28N then sandvik 14C28N