I am no pro on these ones but would say they aren't real rare. Is this the one with the stock running all the way to the muzzle?
I don't know where you are but if you have any gun shows coming to your neck of the woods,I'd be checking that out.
If the gun you were offered is a good deal, it might be easier to just buy it and then part it out, maybe someone else wants what's left and you may not loose a whole bunch in the deal. Just my 2 cents of course.
Best of luck!
Noel
Forgot to mention, if you are in the Calgary area, ther is a gun show at the Thorncliffe community center on January 14th. Loads of stuff shows up there. ALso keep a watch in the upcoming events forum here for gun shows in your area.