Rear shock settings...d600

Have been trying to find a definite stock setting for my rear shock. (2003).
Seems to be between 40 and 44 mm from the top of thread down to the lock nut. This sound correct?
Mine........ Ah......well.......
Isn't nearly that. It's about 15mm
Put it on an ABBA stand and there's a inch gap between the spring and the lock nut!
Was the previous owner really short and trying to lower rear end? Or is it likely the shocks buggered. Doesn't seem to be knocking or too harsh over bumps tho.
Anyone know the stock settings for it? I'll set it Monday and take a ride out see if she's ok..