Chainsaws

Thanks for the response.  Let me ask a couple questions:

1. All I need to do is find a crankcase from one of these models and it should work on my saw?  
2. Are you sure?  And how can I be?  Just curious where the information is found through Husqvarna?
3. What do the numbers on the bottom line of my tag mean?  I understand how to read the first 3 lines, but I don't know what the last line of numbers is telling me.
4. Finally, and if anyone wants to chime in, I'd like to hear from anyone with rebuild experience.  The saw I'm trying to repair was thrown and driven into the ground when I was felling a tree that turned into a "barbershop" chair.  I knew it was possible, it was an older birch, saw the line splitting up from the cut, and quickly walked away.  I tried to pull the saw out first, but it was already jammed and I wasn't gonna get hurt trying too hard to save it.  The trunk split and fell off from the line of the face cut, spun and drove the saw handle first into the ground, but then missed and fell clear of the saw.  I inspected the saw, reset the chain and bar and everything else seemed fine, so cranked it up and surprisingly it ran.  I was able to buck the whole tree. but there was a lot of oil from the bar.  I figured when the bar moved it had messed up the bar oil distribution system, so i stopped using it and finished cutting with my other chainsaw.  When I got back to my shop I was able to take it apart and have a look.  There's a crease in the crankcase - not even a fracture, but a stress-line -- through the middle of the crankcase and oil chamber.  It was seeping oil pretty heavily by the end.  
5. So, here's my question.  Do you think a saw that went through that sort of thing is worth trying to fix?  I've taken good care of it and it's been a good saw for me.  I bought it in 09 and cut about 4 cords of firewood a year with it until this summer.  I think if I just swap out the crankcase, replace the gaskets and put it back together, it should be fine.  But I've never tried to rebuild a chainsaw.  I wonder if it's worth it to try?  Any thoughts?  

Thanks