K-Mags are fantastic bows!!! I absolutely love mine! One of the best out there (esp. for a production bow) for traipsing around through thick brush, ground blinds, or treestands. the short length means you are WAY less likely to have any clearance issues anywhere. That's my experience anyway.
Sorry I can't help with any of your other questions, except to say that shag08's reply re: draw weight is right from what I've read also.
Congrats on a great find! At that weight I'd think that it would be good for form work, hunting most N. American animals, bowfishing...whatever! Looks like a good all-around bow!